#include <bits/stdc++.h>

#define el '\n'

typedef long long ll;
typedef long double ld;

#define Beevo ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

using namespace std;

void testCase() {
    int n, m, k;
    cin >> n >> m >> k;

    if (k > min(n, m))
        return cout << "Impossible", void();

    cout << "Possible" << el;

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (k && i == j)
                cout << '*', k--;
            else
                cout << '.';
        }

        cout << el;
    }
}

signed main() {
    Beevo

    int t = 1;
//    cin >> t;

    while (t--)
        testCase();

    return 0;
}