#include<iostream>
#include<string>
using namespace std;
int main(){
    int N,i;
    long long j,num,max,base,min = 5e18;
    string S;
    long long nums[12];
    cin >> N;
    for(i=0;i<N;i++){
        cin >> S;
        max = 2;
        for(int k=0;k<12;k++) nums[k] = 0;
        for(int k=0;k<S.length();k++){
            if((int)S[k] <= 57){
                nums[k] = (int)S[k] - 48;
            }
            else{
                nums[k] = (int)S[k] - 55;
            }
            if(nums[k] > max) max = nums[k];
        }
        max++;
        base = max;
        num = nums[S.length()-1];
        for(int k=S.length()-2;k>=0;k--){
            num += base*nums[k];
            base *= max;
        }
        if(min > num) min = num;
    }
    cout << min << endl;
    return 0;
}