#ifdef _LOCAL
    #include "local_include.hpp"
#else
    #include <bits/stdc++.h>
    using namespace std;
#endif
#include <ext/pb_ds/assoc_container.hpp>

using namespace __gnu_pbds;

#define fto(i, s, e) for (int i = (s); i <= (e); ++i)
#define fto1(i, s, e) for (int i = (s); i < (e); ++i)
#define fdto(i, s, e) for (int i = (s); i >= (e); --i)
#define fit(it, a) for (auto it = (a).begin(); it != (a).end(); ++it)
#define fat(i, a) for (auto i : (a))

#define ll long long
#define ii pair<int, int>
#define pll pair<ll, ll>
template<class T, class Cmp = less<T>> using oss = tree<T, null_type, Cmp, rb_tree_tag, tree_order_statistics_node_update>;

#define bc __builtin_popcountll
#define y1 ansdj
#define endl '\n'
#define ff first
#define ss second
#define sz(v) int((v).size())
#define all(v) (v).begin(), (v).end()
#define bug(...) _bug(cout, __VA_ARGS__)
#define buga(a, s, e) cout << '{'; if (e < s) cout << '}'; else fto (__i, s, e) cout << a[__i] << " }"[__i == e]; cout << endl

template<class T1, class T2> ostream& operator<<(ostream &os, pair<T1, T2> const &v) {
    return os << '(' << v.ff << ", " << v.ss << ')';
}

template<typename T>
void _bug(ostream &os, T const &var) { os << var << endl; }

template<typename T, typename... Args>
void _bug(ostream &os, T const &var, Args const &... args) {
    os << var << ' ';
    _bug(os, args...);
}

double const pi = acos(-1);
#define oo 1000000007
#define OO 1000000000000000003LL
int const maxn = 1e5+3;

void gcd(int a, int b, ll &x, ll &y) {
    if (b == 0) {
        x = 1;
        y = 0;
    } else {
        gcd(b, a%b, x, y);
        ll tmp = x;
        x = y;
        y = tmp - a/b*y;
    }
}

#define multi_test 1
void _main() {
    int n, s, k;
    cin >> n >> s >> k;
    int b = n-s;
    int g = __gcd(b, __gcd(n, k));
    n /= g, b /= g, k /= g;
    g = __gcd(k, n);
    if (g != 1) bug(-1);
    else {
        ll x, y;
        gcd(k, n, x, y);
        x = x*b % n;
        if (x < 0) x += n;
        bug(x);
    }
}

int main() {
    #ifdef _LOCAL
        freopen("main.inp", "r", stdin);
        freopen("main.out", "w", stdout);
    #endif
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

    int t = 1;
    if (multi_test) cin >> t;
    while (t--) {
        _main();
    }

    #ifdef _LOCAL
        cerr << 0.001*clock() << endl;
    #endif
    return 0;
}
#include <bits/stdc++.h>
using namespace std;

int main() {
  int x, y, z;
  cin >> x >> y >> z;
  if(y*z%x==0){
    cout << (y*z)/x-1 << endl;
  }else{
    cout << (y*z)/x << endl;
  }
}
