#include<stdio.h>
int zettai(int a,int b);
int main(void)
{
    int a=0,b=0;
    scanf("%d%d",&a,&b);
    int a_mirror = a + 1;

    if(a_mirror!=b)
    {
        puts("NO");
        
    }
    else
    {
        puts("YES");
    }
    printf("%d\n",zettai(a_mirror,b));

    return 0;
}
int zettai(int a,int b)
{
    if(a>=b) return (a-b);
    else return (b-a);
}