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# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
class Program
{
	static void Main(string[] args)
	{
		int N = int.Parse(Console.ReadLine());
		string[]A = new string[N];
		long ans = 0;
		long za = 0;
		long ba = 0;
		long bz = 0;
		for(var i=0;i<N;i++){
			A[i] = Console.ReadLine();
			for(var j=0;j<A[i].Length-1;j++){
				if(A[i].Substring(j,2)=="AB"){
					ans++;
				}
			}
			if(A[i].Substring(0,1)=="B"){
				if(A[i].Substring(A[i].Length-1,1)=="A"){
					ba++;
				} else {
					bz++;
				}
			} else if(A[i].Substring(A[i].Length-1,1)=="A"){
				za++;
			}
		}
		if(za>0){
			za--;
			ans+=ba;
			ba=0;
			if(bz>0){
				ans++;
				bz--;
			}
			ans += Math.Min(za,bz);
		} else {
			if(ba>0){
				ans += ba-1;
				ba = 0;
				if(bz>0){
					ans++;
					bz--;
				}
			}
		}
		Console.WriteLine(ans);
	}
}