#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
  vector<int> a[3];
  int n, m;
  for (int i = 1; i <= m; i++) {
    int u, v;
    cin >> u >> v;
    a[u].push_back(v);
  }
  int b[3];
  for (int i = 1; i <= 3; i++) {
    for (int j = 0; j < a[i].size(); j++) {
      b[i - 1] = a[i][j];
      if (a[i][j] < b[0]) {
        b[i - 1] = a[i][j];
      }
    }
  }
  int x = b[0] + b[1] * 10 + b[2] * 100;
  cout << x << '\n';
}
