#include<bits/stdc++.h>
using namespace std;
int main(){
int n,s=0,t;
cin>>n;
if(n%2==0){
while(n!=0){
t=n/10;
n=n%10;
t=t*t;
if(n<10){
break;
}
}
cout<<t;
return 0;
}
while(n!=0){
t=n/10;
n=n%10;
t=t+t;
if(n<10){
break;
}
cout<<t;
return 0;
}
cout<<0;
return 0;
}