#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e6 + 10;
int op;
void solve()
{
    int a, b;
    cin >> a >> b;
    string s1 = "";
    string s2 = "";
    int c1 = 0;
    int c2 = 0;
    int c3 = 0;
    int c4 = 0;
    while (a > 0)
    {
        int t = a % 2;
        a /= 2;
        s1 += to_string(t);
    }
    while (b > 0)
    {
        int t = b % 2;
        b /= 2;
        s2 += to_string(t);
    }
    while (s1.size() < s2.size())
        s1 += "0";
    while (s2.size() < s1.size())
        s2 += "0";
    for (int i = 0; i < s1.size(); i++)
    {
        if (s1[i] == '1')
        {
            if (i & 1)
                c1++;
            else
                c2++;
        }
        if (s2[i] == '1')
        {
            if (i & 1)
                c3++;
            else
                c4++;
        }
    }
    if (c1 != c3 || c2 != c4)
    {
        cout << "Case " << ++op << ": " << -1 << endl;
        return;
    }
    int cnt = 0;
    for (int i = 0; i < s1.size(); i++)
    {
        if (s1[i] != s2[i])
        {
            int j = i;
            if (s1[i] == '0')
            {
                while (j < s1.size() && s1[j] == '0')
                {
                    cnt++;
                    j += 2;
                }
                s1[j] = '0';
                s1[i] = '1';
            }
            else
            {
                while (j < s1.size() && s2[j] == '0')
                {
                    cnt++;
                    j += 2;
                }
                s2[j] = '0';
                s2[i] = '1';
            }
        }
    }
    cout << "Case " << ++op << ": " << cnt << endl;
}
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
    cin >> t;
    while (t--)
        solve();
}