#include<iostream>
using namespace std;
int main()
{
	int a,b,c;
	int flag=0;
	cin >> a >>b >>c;
	int t1,t2,t3;
	while(a%2==0&&b%2==0&&c%2==0) {
		if(a==b&&b==c) {
			cout <<"-1" ;
			return 0;
		}
		t1=a/2;t2=b/2;t3=c/2;
		a=t2+t3;
		b=t1+t3;
		c=t1+t2;
		flag++;
		//cout <<flag<<" "<<a<<" "<<b<<" "<<c<<" "<<endl;
	}
	cout <<flag;
	return 0;
}