// Problem: F. K-hour Clock
// Contest: QOJ - The 2019 ICPC China Shaanxi Provincial Programming Contest
// URL: https://qoj.ac/contest/1285/problem/6727
// Memory Limit: 256 MB
// Time Limit: 1000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include<bits/stdc++.h>
using namespace std;
int main() {
	function<void ()> solve = []() -> void {
		int x, y, z;
		scanf("%d%d%d", &x, &y, &z);
		int k = x + y - z;
		if (k < 0) {
			printf("-1\n");
		}
		else if (k == 0) {
			printf("%d\n", (int)(2e9));
		}
		else {
			printf("%d\n", (k > x && k > z ? k : -1));
		}
		return ;
	};
	int _;
	scanf("%d", &_);
	for (; _; _--) {
		solve();
	}
	return 0;
}