#include <cstdio>
#include <cstdlib>
#include <cstddef>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <string>
#include <iostream>
#include <iomanip>
#include <numeric>
#define L64 long long

int main(void)
{
  int n;
  char a[100];
  std::cin >> n;
  L64 minval = -1;
  for(int i = 0; i < n; i++){
    std::cin >> a;
    int len = (int)strlen(a);
    int digmax = 0;
    for (int j = 0; j < len; j++){
      int digval = 0;
      if(65 <= a[j]) {
        digval = a[j] - 55;
      } else {
        digval = a[j] - 48;
      }
      digmax = std::max(digmax, digval);
    }
    digmax++;
    L64 retval = 0;
    L64 mult = 1;
    for(int j = len - 1; 0 <= j; j--){
      L64 digval = 0;
      if(65 <= a[j]) {
        digval = a[j] - 55;
      } else {
        digval = a[j] - 48;
      }
      retval += mult * digval;
      mult *= (L64)digmax;
    }
    if(i == 0) {minval = retval;}
    else{minval = std::min(minval, retval);}
  }
  std::cout << minval << std::endl;
}