Pbinfo? :)))
#include <iostream>
#include <cmath>
using namespace std;
long long a, b, K, ai, a1, X, n, ni, p;
int main()
{
cin>>n;
ni=n;
while(ni){
p++;
ni=ni/10;
}
K=pow(10,p/2);
b=n%K;
if(p%2==0){
a=n/K;
}else a=n/(K*10);
if(a==0 || b==0){
cout<<a+b;
}else{
while(a%b){
a1=a;
a=b;
b=a1%b;
}
X=b;
cout<<X;}
return 0;
}