#include <cstdlib>
#include <cstdio>
int main()
{
    int n; scanf("%d", &n);
    unsigned long long res=1ULL<<63;
    while (n--) {
        char s[32]; scanf("%s", s);
        char* p=&s[31];
        for(int b=2;b<=36;++b) {
            if (b==16 and s[0]=='0' and s[1]=='X') continue;
            auto t=strtoll(s, &p, b);
            if (*p==0 and res>t) res=t;
        }
    }
    printf("%llu\n", res);
}