#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <unordered_set>
#include <unordered_map>
#include <queue>
#include <ctime>
#include <cassert>
#include <complex>
#include <string>
#include <cstring>
#include <chrono>
#include <random>
#include <bitset>
#include <array>
#include <climits>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <unordered_set>
#include <unordered_map>
#include <queue>
#include <ctime>
#include <cassert>
#include <complex>
#include <string>
#include <cstring>
#include <chrono>
#include <random>
#include <bitset>
#include <array>
#include <climits>

#pragma GCC optimize("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2,fma")

#define ll long long
#define ld  double
using namespace std;

const int N = 5e2 + 5, lg = 19, mod = 998244353;
const int M = 1e6 + 5;
const int b = 31;


int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m, k;
    cin >> n >> m >> k;
    if (min(n, m) < k) {
        cout << "Impossible\n";
        return 0;
    }
    cout << "Possible\n";
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            cout << (i == j ? '*' : '.');
        }
        cout << '\n';
    }
    return 0;
}