#include<stdio.h>
int main()
{
    int A,B,C,D ;
    scanf("%d%d%d%d", &A,&B,&C,&D);
    if (A<=0 || B<=0 || C<=0 || D<=0);
    {
    printf("Yes\n");
    }
    else
    {
       printf("No\n");
    }
    return 0;