#include<bits/stdc++.h>

#define rep(i,n) for(int i=0;i<(int)n;i++)
#define all(c) (c).begin(),(c).end()
#define mp make_pair
#define pb push_back
#define each(i,c) for(__typeof((c).begin()) i=(c).begin();i!=(c).end();i++)
#define dbg(x) cerr<<__LINE__<<": "<<#x<<" = "<<(x)<<endl

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> pi;
const int inf = (int)1e9;
const double INF = 1e12, EPS = 1e-9;

string in;

int main(){
	cin >> in;
	bool allsame = 1;
	int gcd = 0, sum = 0;
	
	for(char c : in){
		if(c != in[0]) allsame = 0;
		gcd = __gcd(gcd, c - '0');
	}
	if(allsame){
		cout << in << endl;
		return 0;
	}
	
	if(gcd > 1) for(char &c : in) c = (c - '0') / gcd + '0';
	for(char c : in) sum += c - '0';
	if(sum % 9 == 0) gcd *= 9;
	else if(sum % 3 == 0) gcd *= 3;
	cout << gcd << endl;
	
	return 0;
}