#include <cstdio>
#include <cmath>

int main( void ){
	int a, b;
	if (!scanf( "%d %d", &a, &b ))
		return 0;
	int c = a - b + 1;
	if (c ==  0){
		printf( "YES\n" );
	}
	else {
		printf( "NO\n" );
	}
	printf( "%d\n", c );
	return 0;
}