import std.stdio;
import std.string;
import std.conv;

void main(){
  auto n = readln.chomp.to!ulong;
  if(n == 1){
    writeln(2);
    return;
  }
  for(auto k = 2; 2UL ^^ (k - 1) <= n; k++){
    if(kbonacci(k, n)){
      writeln(k);
      return;
    }
  }
  writeln(-1);
}

bool kbonacci(int k, ulong n){
  auto a = new ulong[k];
  a[k - 1] = 1;
  ulong s = 1;
  int i = 0;
  while(s < n){
    a ~= s;
    s = s * 2 - a[i];
    i++;
  }
  return s == n;
}