#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:1000000000")
using ll = long long;
using ld = long double;
using namespace std;
const int MAXN = 200001;
int w[MAXN];
int main() {
  ios_base::sync_with_stdio(0);
  cout.setf(ios::fixed);
  cout.precision(20);
  ll a, b, c;
  cin >> a >> b >> c;
  ll s = a + b + c;
  for (int iter = 0; iter < 1000000; iter++) {
    if ((a & 1) || (b & 1) || (c & 1)) {
      cout << iter << endl;
      return 0;
    }
    a = (s - a) / 2;
    b = (s - b) / 2;
    c = (s - c) / 2;
  }
  cout << -1 << endl;
  return 0;
}
