#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define INF 1000000000
#define mod 1000000007
using ll=long long;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    string n,a[3];
    getline(cin,n);
    
    rep(i,3) getline(cin,a[i]);
    if(a[1]==""){
        cout<<"\"assert\"\n";
    }else{
        vector<ll> v;
        rep(i,3){
            ll num=0;
            for(auto c:a[i]){
                num=num*10;
                num+=(c-'0');
            }
            v.push_back(num);
        }
        sort(ALL(v));
        vector<ll> vv;
        rep(i,3)for(int j=i+1;j<3;j++)vv.push_back(v[i]+v[j]);
        sort(ALL(vv));reverse(ALL(vv));
        cout<<vv[1]<<endl;
    }
    return 0;
}