int main()
{
    int a,b,c;
    scanf("%d %d %d",&a,&b,&c);
    if(a>b){
        if(a>c){
            if(b+c>a){
                printf("yes");
            }else{
                printf("no");
            }
        }else {
            if(a+b>c){printf("yes");
            }else{
                printf("no");
            }
        }
    }else{
        if(b>c){
            if(a+c>b){
                printf("yes");
            }else{
                printf("no");
            }
        }else{
            if(a+b>c){
                printf("yes");
            }else{
                printf("no");
            }
        }
    }return 0;
}

#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;
}