#include <bits/stdc++.h>
using namespace std;
const int N = 1E5+5;
int n,sum1;
bool f;
int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
        string s;
        cin>>s;
        if(s=="0"){
            cout<<0;
            return 0;
        }
        int sum2=0,sum=sum1;
        for(int j=0;j<s.size();j++){
            if(s[j]=='0') sum1++;
            else if(s[j]!='1'){
                cout << s;
                f=1;
                sum1=sum;
                break;
            }
            else sum2++; 
        }
        if(sum2>1){
            cout<<s;
            f=1;
            sum1=sum;
        }
        else if(s=="1") continue;
        else if(sum2==s.size()){
            cout<<s;
            f=1;
        }
    }
    if(f==0) cout<<1;
    for(int i=1;i<=sum1;i++) cout<<0;
    return 0;
}