#include<iostream>
using namespace std;
int main()
{
	int n;
	int a,b,c;
	int x,y,z;
	int count=0;
	cin>>a>>b>>c;
	while(1)
	{
		x=(b+c)/2;
		y=(a+c)/2;
		z=(a+b)/2;
		count++;
		if(x%2==1||y%2==1||z%2==1)
		break;
		a=x;
		b=y;
		c=c;
		if(count>=200)
		break;
	}
	if(count<200)
	cout<<count;
	else cout<<"-1";
}