#include <stdio.h>
int main()
{ double a,b,c,d;
scanf("%lf %lf %lf %lf",&a,&b,&c,&d);
if(a==c&&b==d){
printf("YES");
}else if(a=b&&c==d){
printf("YES");
}else if(a=d&&c==b){
printf("YES");
}else{
printf("NO");
}
return 0;
}