#include <bits/stdc++.h>
#define PI 3.14159265359
using namespace std;
const int64_t mod = 1e9 + 7;

int main() {
	string N, A, B, C;
	getline(cin, N);
	getline(cin, A);
	getline(cin, B);
	getline(cin, C);

	if ((A.size() > 1) || (B.size() > 1)) {
		cout << "assert" << endl;
	}
	else {
		vector<int> v(3);
		v.at(0) = stoi(A);
		v.at(1) = stoi(B);
		v.at(2) = stoi(C);
		sort(v.begin(), v.end());

		int n;
		if (v.at(0) == v.at(1)) {
			n = v.at(0) + v.at(1);
		}
		else {
			n = v.at(0) + v.at(2);
		}

		cout << n << endl;
	}
}