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 Lua (5.3.2) (judge verdict: Runtime Error)

r,g,b,n=io.read("*n","*n","*n","*n")

counter=0
for i=0,n do
    for j=0,n-i do
        rg=r*i+g*j
        if n>=rg and (n-rg)%b==0 then
            counter=counter+1
        end
    end
end
print(counter)