#include<bits/stdc++.h>

#define int long long

using namespace std;

signed main(){
    int t;
    cin >> t;
    while(t--) {
        int a, b, c;
        cin >> a >> b >> c;
        if(c == 0){
            cout << -1 << '\n';
        }else if(a == 0){
            if(b == 0 && c == 1){
                cout << 0 << '\n';
            }else if(b > 0 && c == 1){
                cout << b << '\n';
            }else{
                cout << -1 << '\n';
            }
        }else if(b == 0){
            if(a + 1 == c){
                cout << a << '\n';
            }else{
                cout << -1 << '\n';
            }
        }else{
            if(a + b == c){
                cout << a << '\n';
            }else if(a + 1 == c){
                int h = 1, floor = 1;
                while(true){
                    if(a - floor > 0){
                        a -= floor;
                        floor *= 2;
                        h++;
                    }else{
                        break;
                    }
                }
                b = b - (floor - a);
                while(true){
                    b -= floor;
                    h++;
                    if(b < 0){
                        break;
                    }
                }
                cout << h<< '\n';
            }else{
                cout << -1 << '\n';
            }
        }
    }
}