#include<iostream>
#include<cstdio>
#include<string>
#include<bits/stdc++.h>
#define LL long long
using namespace std;
const int INF=0x3f3f3f3f;
const int N=2e5+10;
int a,b,c;
int main(){
	cin>>a>>b>>c;
	if(max(a,max(b,c))<min(a,min(b,c))+a+b+c-max(a,max(b,c))-min(a,min(b,c))){
		cout<<"yes";
	}else{
		cout<<"no";
	}
}