Problem:
Score : 100 points

Problem Statement

Snuke has N integers: 1,2,\ldots,N.
He will choose K of them and give those to Takahashi.

How many ways are there to choose K consecutive integers?

Constraints

All values in input are integers.

1 \leq K \leq N \leq 50

Input

Input is given from Standard Input in the following format:

N K

Output

Print the answer.

Sample Input 1

3 2

Sample Output 1

2

There are two ways to choose two consecutive integers: (1,2) and (2,3).

Sample Input 2

13 3

Sample Output 2

11

Solution in JavaScript (node.js v5.12) (judge verdict: Runtime Error)

function main(input) {
  // K個の連続数の一番最初の数をFとして
  // ex) 三個の連続数ならばF,F+1,F+2が該当すれば一回とカウントする
  // Fこの場合F+2が存在しなければループを抜けるものとする
  
  let continuityNum = input.split(" ")[0];
  let selectNum = input.split(" ")[1];
  
  let nowNum = 0;
  let endFlg = 0;
  
  while(1){
    var count = 1++;

    var judge　= nowNum;
    if(judge + selectNum -1 < continuityNum){
        nowNum++;
   	}else{
    endFlg = 1;
    }
    
    if(endFlg === 1){
      console.log(count);
      break;
    }
  }
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));