#include <iostream>
using namespace std;
bool triangle(int a, int b, int c){
return (a+b>c)&&(b+c>a)&&(c+a>b);
}
int main() {
int a,b,c,d;
cin >> a >> b >> c >> d;
if(
triangle(a,b,c)||
triangle(d,b,c)||
triangle(a,d,c)||
triangle(a,b,d)
){
cout << "YES";
}
else{
cout << "NO";
}
}
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