#include <bits/stdc++.h>

#define pb push_back
#define mp make_pair
#define sz(x) (int)(x).size()
#define li long long
#define ld long double
#define x first
#define y second
#define pt pair<int, int>
#define pll pair<ll, ll>
#define forn(i, t) for(int i = 0; i < (t); i++)
#define fore(i, f, t) for(int i = (f); i < (t); i++)
#define forr(i, f, t) for(int i = (f) - 1; i >= (t); i--)
#define all(x) (x).begin(), (x).end()
#define ins insert

using namespace std;


const int INF = 1e9;
const int MOD = 1e9 + 7;
const li INF64 = 1e18;
const ld EPS = 1e-7;

mt19937 myrand(time(NULL));

int n, m, k;


bool read(){
    if(scanf("%d%d%d", &n, &m, &k) != 3)
        return 0;
    return 1;
}


void solve(int num){
    int ans = INF;
    if (n >= 2 * k + 3 && m >= k + 1)
        ans = min(ans, (m + k - 1) / k);
    if (m >= 2 * k + 3 && n >= k + 1)
        ans = min(ans, (n + k - 1) / k);
    if (n >= 4 * k + 1 && m >= k + 2)
        ans = min(ans, 5);
    if (m >= 4 * k + 1 && n >= k + 2)
        ans = min(ans, 5);
    if (n >= 3 * k + 1 && m >= k + 2 && k > 1)
        ans = min(ans, 4);
    if (m >= 3 * k + 1 && n >= k + 2 && k > 1)
        ans = min(ans, 4);
    printf("Case #%d: ", num);
    printf("%d\n", ans == INF ? -1 : ans);
}


int main(){
    #ifdef _DEBUG
        freopen("subtle_sabotage.txt", "r", stdin);
    #endif
    int n;
    scanf("%d", &n);
    forn(i, n){
        read();
        solve(i + 1);
    }
    return 0;
}