#include <bits/stdc++.h> using namespace std; #define REP(i, n) for (int i = (int)(0); i < (int)(n); ++i) #define REPS(i, n) for (int i = (int)(1); i <= (int)(n); ++i) #define RREP(i, n) for (int i = ((int)(n)-1); i >= 0; i--) #define RREPS(i, n) for (int i = ((int)(n)); i > 0; i--) #define IREP(i, m, n) for (int i = (int)(m); i < (int)(n); ++i) #define IREPS(i, m, n) for (int i = (int)(m); i <= (int)(n); ++i) #define FOR(e, c) for (auto &e : c) #define SORT(v, n) sort(v, v + n); #define VSORT(v) sort(v.begin(), v.end()); #define RVISORT(v) sort(v.begin(), v.end(), greater<int>()); #define ALL(v) v.begin(), v.end() #define MP(n, m) make_pair(n, m); using VI = vector<int>; using VVI = vector<VI>; using PII = pair<int, int>; using ll = long long; using ul = unsigned long; typedef long long ll; template<class T, class C> void chmax(T& a, C b){ a>b?:a=b; } template<class T, class C> void chmin(T& a, C b){ a<b?:a=b; } const int mod=1e9+7; void printv(VI& v){ REP(i,v.size()) cout << v[i] << " "; cout << endl; } int vtotal(VI& v){ int total=0; REP(i,v.size()) total+=v[i]; return total; } int main() { cin.tie( 0 ); ios::sync_with_stdio( false ); string n; getline(cin,n); int num=stoi(n); vector<ll> v; REP(i,num){ string s; getline(cin,s); if(s.find(" ")!= std::string::npos){ cout<<"\"assert\""<<endl; return 0; } v.push_back(stoll(s)); } vector<ll> v2; v2.push_back(v[0]+v[1]); v2.push_back(v[2]+v[1]); v2.push_back(v[0]+v[2]); VSORT(v2); if(v2[1]==v2[2])cout<<v2[0]<<endl; else cout<<v2[1]<<endl; return 0; }