## Decreasing Srrnmieeda October Cook off challenge Solution | Easy Explain Decreasing Srrmieeda-

Easy Explanation of Decreasing Srrnmieeda October Cook-off challenge Solution  With Code.Here Is Problem Statement.

## Problem Statement-

You are given two integers $L$ and $R$. Find the smallest non-negative integer $N$ such that

$N\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}L>N\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}\left(L+1\right)>\dots >N\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}\left(R-1\right)>N\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}R\phantom{\rule{thinmathspace}{0ex}}.$

Here, $\mathrm{%}$ is the modulo operator, so $A\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}B$ is the remainder of $A$ after division by $B$. For example, $11\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}3=2$.

### Input

• The first line of the input contains a single integer $T$ denoting the number of test cases. The description of $T$ test cases follows.
• The first and only line of each test case contains two space-separated integers $L$ and $R$.

### Output

For each test case, print a single line containing one integer ― the smallest possible $N$, or $-1$ if no solution exists.

It is guaranteed that when a solution exists, the smallest solution does not exceed ${10}^{18}$.

### Constraints

• $1\le T\le {10}^{5}$
• $1\le L

### Example Input

2
4 6
1 2


### Example Output

6
-1


### Explanation

Example case 1: $N=6$ satisfies the given condition, since $6\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}4\phantom{\rule{thinmathspace}{0ex}}\left(=2\right)>6\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}5\phantom{\rule{thinmathspace}{0ex}}\left(=1\right)>6\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}6\phantom{\rule{thinmathspace}{0ex}}\left(=0\right)$. Notice that $N=7$ also satisfies the condition, but it is larger.

Example case 2: It is impossible to find a valid solution because for any non-negative integer $N$, we have $N\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}1\phantom{\rule{thinmathspace}{0ex}}\left(=0\right)\le N\phantom{\rule{thinmathspace}{0ex}}\mathrm{%}\phantom{\rule{thinmathspace}{0ex}}2$.

Join Telegram For Competetive Programming Guide and Update

### Decreasing Srrnmieeda  Solution -

In this Problem  given that N%L>N%(L+1)>>N%(R1)>N%R.  and L< R

1-So for satisfying first relationship N should be between >=R otherwise condition one cannot be satisfied.
2-But we know that if N is divisible by L so we  if N> R it is not possible to obtain the relation 1 that is
N%L>N%(L+1)>>N%(R1)>N%R.

According to those two statements, What can be the max value of N%L? Maxmimum value of N%L cannot
exceed 2*L so N<2*L.
and if if(R >= 2*L) we cannot obtain sequence .

so Final Logic is -
if(R >= 2*L) cout << -1 << '\n'; else cout << R << '\n';

### codeforces rating system | Codeforces rating Newbie to Legendary Grandmaster

Codeforces rating system | Codeforces rating Newbie to Legendary Grandmaster- Codeforces is one of the most popular platforms for competitive programmers and  codeforces rating matters a lot  .  Competitive Programming  teaches you to find the easiest solution in the quickest possible way. CP enhances your problem-solving and debugging skills giving you real-time fun. It's brain-sport. As you start solving harder and harder problems in live-contests your analytical and rational thinking intensifies. To have a good codeforces profile makes a good impression on the interviewer. If you have a good  codeforces profile so it is very easy to get a referral for product base company like amazon, google , facebook etc.So in this blog I have explained everything about codeforces rating system. What are different titles on codeforces- based on rating codeforces divide rating into 10 part. Newbie Pupil Specialist Expert Candidate Codemaster Master International Master Grandmaster Internat

### Apple Division CSES Problem Set Solution | CSES Problem Set Solution Apple division with code

Apple Division CSES Problem Set Solution | CSES Problem Set Solution Apple division with code - Apple Division CSES Problem Solution Easy Explanation. Apple division is problem is taken form cses introductory problem set.Let's Read Problem statement first. Problem Statement- Time limit:  1.00 s   Memory limit:  512 MB There are  n n  apples with known weights. Your task is to divide the apples into two groups so that the difference between the weights of the groups is minimal. Input The first input line has an integer  n n : the number of apples. The next line has  n n  integers  p 1 , p 2 , … , p n p 1 , p 2 , … , p n : the weight of each apple. Output Print one integer: the minimum difference between the weights of the groups. Constraints 1 ≤ n ≤ 20 1 ≤ n ≤ 20 1 ≤ p i ≤ 10 9 1 ≤ p i ≤ 10 9 Example Input: 5 3 2 7 4 1 Output: 1 Explanation: Group 1 has weights 2, 3 and 4 (total weight 9), and group 2 has weights 1 and 7 (total weight 8). Join Telegram channel for code discussi

### Movie Festival CSES problem set solution

Movie Festival CSES problem set solution - Problem statement-  Time limit:  1.00 s   Memory limit:  512 MB In a movie festival  n n  movies will be shown. You know the starting and ending time of each movie. What is the maximum number of movies you can watch entirely? Input The first input line has an integer  n n : the number of movies. After this, there are  n n  lines that describe the movies. Each line has two integers  a a  and  b b : the starting and ending times of a movie. Output Print one integer: the maximum number of movies. Constraints 1 ≤ n ≤ 2 ⋅ 10 5 1 ≤ n ≤ 2 ⋅ 10 5 1 ≤ a < b ≤ 10 9 1 ≤ a < b ≤ 10 9 Example Input: 3 3 5 4 9 5 8 Output: 2 Solution - Step -1 take input in a vector as a pair first element is ending time ans second element is starting time Step -2 sort the vector in increasing order because we will watch that movie which is ending first. Step -3 iterate over vector and calculate ans .           follow code below-