#include <iostream>
using namespace std;
int main() {
long double x,y,z;
cin >> x >> y >> z;
cout << ((x+y>=z)&&(x+z>=y)&&(y+z>=x) ? "YES": "NO");
return 0;
}
I2luY2x1ZGUgPGlvc3RyZWFtPgp1c2luZyBuYW1lc3BhY2Ugc3RkOwogCmludCBtYWluKCkgewoJbG9uZyBkb3VibGUgeCx5LHo7CgljaW4gPj4geCA+PiB5ID4+IHo7Cgljb3V0IDw8ICgoeCt5Pj16KSYmKHgrej49eSkmJih5K3o+PXgpID8gIllFUyI6ICJOTyIpOwoJcmV0dXJuIDA7Cn0=