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 C++14 (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include <iostream>
#include <string>
using namespace std;

int main(){
  int R,G,B,N;
  int r = 0,g  = 0,b = 0;
  int result = 0;
  cin >> R >> G >> B >> N ;
  for(r = 0; R*r<= N; ++r){
      for(g = 0; R*r + G*g <= N; ++g){
          for(b = 0; R*r + G*g + B*b <= N; ++b){
            if(N == R*r + G*g + B*b ){++result;}      
          }
      }
  }
  cout << result << endl;
}