#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using pd = pair<double, double>;
using pld = pair<ld, ld>;


ll gcd(ll a, ll b)
{
    while (b)
    {
        ll aux = b;
        b = a % b;
        a = aux;
    }
    return a;
}


int main()
{
    auto mod_inverse = [](const ll p, const ll m)
    {
        auto ext_euclid = [](const ll a, const ll b)
        {
            ll old_r = a, r = b;
            ll old_s = 1, s = 0;
            ll old_t = 0, t = 1;
            ll q, new_r, new_s, new_t;
            while (r != 0)
            {
                q = old_r / r;
                new_s = old_s - s * q;
                new_t = old_t - t * q;
                new_r = old_r % r;
                old_r = r, r = new_r;
                old_s = s, s = new_s;
                old_t = t, t = new_t;
            }
            return old_s;
        };
        ll modular_inverse = ext_euclid(p, m);
        if (modular_inverse < 0)
        {
            modular_inverse += m;
        }
        return modular_inverse;
    };
    
    ios::sync_with_stdio(0);
    cin.tie(0);

    int T;
    cin >> T;

    while (T--)
    {
        ll N, S, K;
        cin >> N >> S >> K;
        ll their_gcd = gcd(K, N);

        if ((N - S) % their_gcd)
        {
            cout << "-1\n";
        }
        else
        {
            const ll K1 = K / their_gcd, P1 = (N - S) / their_gcd, N1 = N / their_gcd;

            cout << (P1 * mod_inverse(K1, N1)) % N1 << "\n";
        }
    }
}

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

#define CPP_STR(x) CPP_STR_I(x)
#define CPP_CAT(x, y) CPP_CAT_I(x, y)
#define CPP_STR_I(args...) #args
#define CPP_CAT_I(x, y) x##y

#define ASSERT(expr...) assert((expr))

using i8 = int8_t;
using u8 = uint8_t;
using i16 = int16_t;
using u16 = uint16_t;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;

using f32 = float;
using f64 = double;
// }}}

constexpr i64 INF = 1'010'000'000'000'000'017LL;

constexpr i64 MOD = 1'000'000'007LL;

constexpr f64 EPS = 1e-12;

constexpr f64 PI = 3.14159265358979323846;

#define M5 100007
#define M9 1000000000

// util {{{
#define FOR(i, start, end) for (i64 i = (start), CPP_CAT(i, xxxx_end) = (end); i < CPP_CAT(i, xxxx_end); ++i)
#define REP(i, n) FOR(i, 0, n)

#define ALL(f, c, ...) (([&](decltype((c)) cccc) { return (f)(std::begin(cccc), std::end(cccc), ##__VA_ARGS__); })(c))
#define ll long long int
#define VI vector<int>
template <typename C>
i64 SIZE(const C &c)
{
    return static_cast<i64>(c.size());
}

template <typename T, size_t N>
i64 SIZE(const T (&)[N]) { return static_cast<i64>(N); }

template <typename T, typename U, typename Comp = less<>>
bool chmax(T &xmax, const U &x, Comp comp = {})
{
    if (comp(xmax, x))
    {
        xmax = x;
        return true;
    }
    return false;
}

template <typename T, typename U, typename Comp = less<>>
bool chmin(T &xmin, const U &x, Comp comp = {})
{
    if (comp(x, xmin))
    {
        xmin = x;
        return true;
    }
    return false;
}
// }}}

// init {{{
struct ProconInit
{
    static constexpr int IOS_PREC = 15;
    static constexpr bool AUTOFLUSH = false;

    ProconInit()
    {
        cin.tie(nullptr);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(IOS_PREC);
        if (AUTOFLUSH)
            cout << unitbuf;
    }
} PROCON_INIT;
// }}}

//--------------------------------------------------------------------

bool isOK(int mid, double key)
{
}

int binary_search(double key)
{
    int left = -1; //「index = 0」が条件を満たすこともあるので、初期値は -1
    int right = 2000000000;
    /* どんな二分探索でもここの書き方を変えずにできる！ */
    while (right - left > 1)
    {
        int mid = left + (right - left) / 2;

        if (isOK(mid, key))
            right = mid;
        else
            left = mid;
    }

    /* left は条件を満たさない最大の値、right は条件を満たす最小の値になっている */
    return right;
}

bool isKaibun(string st)
{
    bool ans = true;
    int n = st.length();
    REP(i, n / 2)
    {
        if (st[i] != st[n - i - 1])
        {
            return false;
        }
    }
    return true;
}

int toInt(char a)
{
    return a - '0';
}

int gcd(int a, int b)
{
    if (a % b == 0)
    {
        return (b);
    }
    else
    {
        return (gcd(b, a % b));
    }
}

int lcm(int a, int b)
{
    return a * b / gcd(a, b);
}

void solve()
{
    int a, b, c;
    cin >> a >> b;
    if (a != b)
    {
        cout << (3 - (a + b)) % 3 << endl;
    }
    else
    {
        cout << a << endl;
    }
}

signed main()
{

    solve();

    return 0;
}
