#include <iostream>
#include <vector>
#include <queue>
using namespace std;

int main(){
  long long n;cin>>n;
  if(n == 1){
    cout << 2 << endl;
    return 0;
  }
  long long nwi = 2;
  queue<long long> X;
  while(1){
    if(n < (1LL<<(nwi-1)))break;
    long long nw = 1;
    long long sm = 0;
    while(X.size())X.pop();
    while(n > nw){
      sm += nw;
      X.push(nw);
      if(X.size() > nwi){
        sm -= X.front(); X.pop();
      }
      nw = sm;
    }
    if(nw == n){
      cout << nwi << endl;
      return 0;
    }
    nwi++;
  }
  cout << -1 << endl;
}