tijie

#include <bits/stdc++.h>
using namespace std;
int a,b,c;
void s(int a,int b,int c){
if(a+b>c&&a+c>b&&c+b>a) cout<<"yes";
else cout<<"no";
}
int main (){
cin>>a>>b>>c;
s(a,b,c);
return 0;
}