#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000000000000

bool is_ok(long long n,long long p){
	vector<long long> x;
	while(n!=0){
		x.push_back(n%p);
		n/=p;
	}
	
	rep(i,x.size()-1){
		if(x[i]!=x[i+1])return false;
	}
	///cout<<p<<','<<x.size()<<endl;
	//cout<<x[0]<<endl;
	return true;
}

int main(){
	
	long long N;
	cin>>N;
	vector<long long> Y;
	for(long long i=2;i<=1000005;i++){
		if(is_ok(N,i)){
			cout<<i<<endl;
			return 0;
		}
		if(N%i==0){
			Y.push_back(i);
			Y.push_back(N/i);
		}
	}
	Y.push_back(N);
	sort(Y.begin(),Y.end());
	
	rep(i,Y.size()){
		if(Y[i]<=2)continue;
		if(is_ok(N,Y[i]-1)){
			cout<<Y[i]-1<<endl;
			return 0;
		}
	}
	
	cout<<N+1<<endl;
	
	return 0;
}