#include <stdio.h>

int main(void)
{
    int x,y,x2,y2;
    scanf("%d%d%d%d",&x,&y,&x2,&y2);
    if(x==y&&x2==y2&&x>x2)printf("%d",x+1);
    else if(x>y)printf("%d",x);
    else printf("%d",y);
    return 0;
}