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 Python (3.4.3) (judge verdict: Runtime Error)

N = int(input())
res=0
first, end, both = 0, 0, 0


for i in range(N):
    str = input()
    res+=str.count("AB")
    if str[0]=="B":
        first+=1
    if str[-1]=="A":
        end+=1
    if str[0]=="B" and str[-1]=="A":
        both+=1

res+=min(first, end)
if both==max(first, end) and both!=0:
    res-=1

print(res)