#include <bits/stdc++.h>
#define rep(i,n) for ((i)=1;(i)<=(n);(i)++)
#define per(i,n) for ((i)=n;(i)>=(1);(i)--)
using namespace std;

long long a,b,c,s;
int main(){
	cin>>a>>b>>c;
	while(!(a&1)&&!(b&1)&&!(c&1)){
		s++;
		int ta=a/2,tb=b/2,tc=c/2;
		a=tb+tc;b=ta+tc;c=ta+tb;
		if(s>1000000){
			puts("-1");
			return 0;
		}
	}
	cout<<s<<endl;
	return 0; 
}