2019 ICPC Asia Xuzhou A - Cat Jisuanke- 42540

#pragma warning (disable:4996)
#include <iostream>
#include <algorithm>
#include <iomanip>
#include <cstring>
#include <string>
#include <cstdio>
#include <cmath>
#include <fstream>
#include <vector>
#include <set>
typedef long long ll;
typedef unsigned long long ull;
using namespace std;

int main() {
    
    
	int T;
	scanf("%d", &T);
	while (T--) {
    
    
		ull l, r, s;
		scanf("%llu%llu%llu", &l, &r, &s);
		if (l == r) {
    
    
			if (s >= l || s >= r)
				printf("1\n");
			else
				printf("-1\n");
		}
		else if (r - l + 1 == 2) {
    
    
			if (s >= (r ^ l))
				printf("2\n");
			else if (s >= r || s >= l)
				printf("1\n");
			else
				printf("-1\n");
		}
		else {
    
    
			if ((r - l + 1) % 2 == 0) {
    
    //长度偶
				if (l % 2 == 0) {
    
    //偶开始 
					ull tmp = (r - l + 1) / 2;
					if (tmp % 2 == 0)
						printf("%llu\n", r - l + 1);
					else {
    
    
						if (s >= 1)
							printf("%llu\n", r - l + 1);
						else {
    
    //s==0
							if (s >= (1 ^ (l + 1)) || s >= (1 ^ (r - 1)))
								printf("%llu\n", r - l + 1 - 1);
							else
								printf("%llu\n", r - l + 1 - 2);
						}
					}
				}
				else {
    
    //奇开始
					ull tmp = (r - l + 1 - 2) / 2;
					if (tmp % 2 == 0) {
    
    
						if (s >= (r ^ l))
							printf("%llu\n", r - l + 1);
						else if (s >= r || s >= l)
							printf("%llu\n", r - l + 1 - 1);
						else
							printf("%llu\n", r - l + 1 - 2);
					}
					else {
    
    
						if (s >= 1) {
    
    
							if (s >= (1 ^ r ^ l))
								printf("%llu\n", r - l + 1);
							else if (s >= (1 ^ r) || s >= (1 ^ l))
								printf("%llu\n", r - l + 1 - 1);
							else
								printf("%llu\n", r - l + 1 - 2);
						}
						else {
    
     //s==0
							if (s >= (1 ^ l) || s >= (1 ^ r))
								printf("%llu\n", r - l + 1 - 1);
							else if (r - l + 1 - 2 - 2 > 0)
								printf("%llu\n", r - l + 1 - 2 - 2);
							else
								printf("-1\n");
						}
					}
				}
			}
			else {
    
    //长度奇
				if (l % 2 == 0) {
    
    //偶开始
					ull tmp = (r - l + 1 - 1) / 2;
					if (tmp % 2 == 0) {
    
    
						if (s >= r)
							printf("%llu\n", r - l + 1);
						else
							printf("%llu\n", r - l + 1 - 1);
					}
					else {
    
    
						if (s >= 1) {
    
    
							if (s >= (1 ^ r))
								printf("%llu\n", r - l + 1);
							else
								printf("%llu\n", r - l + 1 - 1);
						}
						else {
    
     //s==0
							if (s >= (1 ^ r))
								printf("%llu\n", r - l + 1);
							else if (r - l + 1 - 3 > 0)
								printf("%llu\n", r - l + 1 - 3);
							else
								printf("-1\n");
						}
					}
				}
				else {
    
    //奇开始
					ull tmp = (r - l + 1 - 1) / 2;
					if (tmp % 2 == 0) {
    
    
						if (s >= l)
							printf("%llu\n", r - l + 1);
						else
							printf("%llu\n", r - l + 1 - 1);
					}
					else {
    
    
						if (s >= 1) {
    
    
							if (s >= (1 ^ l))
								printf("%llu\n", r - l + 1);
							else
								printf("%llu\n", r - l + 1 - 1);
						}
						else {
    
     //s==0
							if (s >= (1 ^ l))
								printf("%llu\n", r - l + 1);
							else if (r - l + 1 - 3 > 0)
								printf("%llu\n", r - l + 1 - 3);
							else
								printf("-1\n");
						}
					}
				}
			}
		}
	}
	return 0;
}