Askar

#include <bits/stdc++.h>

using namespace std;

int n, a[3][7], pr[1500];

int main(){
  cin >> n;
  for(int i = 0; i <= 2; i++){
    for(int j = 0; j < 7; j++){
      a[i][j] = 0;
    }
  }
  for(int i = 0; i < n; i++){
    for(int j = 1; j <= 6; j++){
      cin >> a[i][j];
    }
  }
  for(int i = 1; i <= 6; i++){
    if(!a[0][i])
      continue;
    pr[a[0][i]] = 1;
    if(n >= 2){
      for(int j = 0; j <= 6; j++){
        pr[a[0][i]*10+a[1][j]] = 1;
        if(n == 3){
          for(int l = 0; l <= 6; l++){
            pr[a[0][i]*100+a[1][j]*10+a[2][l]] = 1;
          }
        }
      }
      for(int j = 0; j <= 6; j++){
        pr[a[0][i]*10+a[2][j]] = 1;
        if(n == 3){
          for(int l = 0; l <= 6; l++){
            pr[a[0][i]*100+a[2][j]*10+a[1][l]] = 1;
          }
        }
      }
    }
  }
  for(int i = 1; i <= 6; i++){
    if(!a[1][i])
      continue;
    pr[a[1][i]] = 1;
    if(n >= 2){
      for(int j = 0; j <= 6; j++){
        pr[a[1][i]*10+a[0][j]] = 1;
        if(n == 3){
          for(int l = 0; l <= 6; l++){
            pr[a[1][i]*100+a[0][j]*10+a[2][l]] = 1;
          }
        }
      }
      for(int j = 0; j <= 6; j++){
        pr[a[1][i]*10+a[2][j]] = 1;
        if(n == 3){
          for(int l = 0; l <= 6; l++){
            pr[a[1][i]*100+a[2][j]*10+a[0][l]] = 1;
          }
        }
      }
    }
  }
  for(int i = 1; i <= 6; i++){
    if(!a[2][i])
      continue;
    pr[a[2][i]] = 1;
    if(n >= 2){
      for(int j = 0; j <= 6; j++){
        pr[a[2][i]*10+a[0][j]] = 1;
        if(n == 3){
          for(int l = 0; l <= 6; l++){
            pr[a[2][i]*100+a[0][j]*10+a[1][l]] = 1;
          }
        }
      }
      for(int j = 0; j <= 6; j++){
        pr[a[2][i]*10+a[1][j]] = 1;
        if(n == 3){
          for(int l = 0; l <= 6; l++){
            pr[a[2][i]*100+a[1][j]*10+a[0][l]] = 1;
          }
        }
      }
    }
  }

  for(int i = 1; i <= 1000; i++){
    if(!pr[i]){
      cout << i-1 << endl;
      return 0;
    }
  }
}