#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define Sz(x) (int)(x).size()
#define bit(x) (1ll << (x))
using ll = long long;
using db = double;
using ull = unsigned long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vii = vector<vi>;
using vl = vector<ll>;
using vll = vector<vl>;
using vs = vector<string>;
using vd = vector<db>;
mt19937 mrand(time(0));

void solve(void)
{
	int x, y, z;
	cin >> x >> y >> z;
	if (x + y < z) cout << -1 << "\n";
	else if (x + y == z) cout << z + 1 << "\n";
	else
	{
		int k = x + y - z;
		if (k <= max({x, z}))
			cout << -1 << "\n";
		else
			cout << k << "\n";
	}
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	// cout << fixed << setprecision(10);

	int T = 1;
	cin >> T;
	for (int i = 1; i <= T; i++)
	solve();

	return 0;
}