#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,m,h;
	cin>>n>>m>>h;
	if(n+m>h&&n+h>m&&m+h>n){
		cout<<"Yes";
	}else{
		cout<<"No";
	}
}
/**************************************************************
	Problem: 1045
	User: wangyiyang
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/