#include <bits/stdc++.h>
#define rep(i,n) for (int i=0; i<(n); ++i)
using namespace std;
using ll=long long;
int main(){
    ll n;
    cin>>n>>ws;
    string s;
    getline(cin,s);
    if(s.find(' ')!=s.npos){
        cout<<"assert"<<endl;
        return 0;
    }
    ll a=atol(s.c_str()),b,c; 
    cin>>b>>c;
    vector<ll>r({a+b,b+c,c+a});
    sort(r.begin(),r.end());
    if(r[2]==r[1])cout<<r[0]<<endl;
    else cout<<r[1]<<endl;
}