#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <stdlib.h>
#define llint long long

using namespace std;

int n;
vector<string> vec;
vector<llint> vec2;

llint get(string s)
{
	llint ret = 0, mul = 1;
	reverse(s.begin(), s.end());
	for(int i = 0; i < s.size(); i++) ret += mul*(s[i]-'0'), mul *= 10;
	return ret;
}

int main(void)
{
	string s;
	while(getline(cin, s)){
		vec.push_back(s);
	}
	if(vec.size() == 2){
		cout << "\"assert\"" << endl;
		return 0;
	}
	
	vec2.push_back(get(vec[1]) + get(vec[2]));
	vec2.push_back(get(vec[1]) + get(vec[2]));
	vec2.push_back(get(vec[2]) + get(vec[3]));
	sort(vec2.begin(), vec2.end());
	vec2.erase(unique(vec2.begin(), vec2.end()), vec2.end());
	reverse(vec2.begin(), vec2.end());
	
	cout << vec2[1] << endl;
	
	return 0;
}