#include <iostream>#include <cstdlib>#include <vector>#include <algorithm>using namespace std;bool mycmp(const string& a, const string& b) {    string ta = a + b;    string tb = b + a;        int len = ta.length();        for (int i=0; i<len; i++) {        if (ta[i] > tb[i]) {            return false;        } else if (ta[i] < tb[i]){            return true;        }    }    return true;}bool print_no_leading_zero(string &n) {    int len = n.length();    bool full_zero = true;    int i;    for (i=0; i<len; i++) {        if (n[i] != ‘0‘) {            full_zero = false;            break;        }    }    while (i<len) {        cout<<n[i++];    }    return full_zero;}int main() {    string is;    int N = 0;    cin>>N;        vector<string> segs(N);    for (int i=0; i<N; i++) {        cin>>segs[i];    }        int len = segs.size();    sort(segs.begin(), segs.end(), mycmp);        bool zero = true;    if (len > 0) {        for (int i=0; i<len; i++) {            if (zero) {                zero = print_no_leading_zero(segs[i]);            } else {                cout<<segs[i];            }        }            }     if (len < 1 || zero) {        cout<<0;    }    cout<<endl;    return 0;}