#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int main() 
{
    
    int m,n,count=0,t;
    
    scanf("%d %d",&n,&m);
    t = n - m;
    while(t!=0)
    {
        count++;        
        t = t-1;
    }
    
    printf("%d",count);
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */    
    return 0;
}