#include<bits/stdc++.h>
using namespace std;
int main()
{
	int a,b,c;
	cin>>a>>b>>c;
	
	if(a+b>c && a+c>b && b+c>a){
	     cout<<"Yes"<<endl;
	}else{
		 cout<<"NO"<<endl;
	} 

	return 0;
}

/**************************************************************
	Problem: 1045
	User: czr
	Language: C
	Result: Compile Error
****************************************************************/