#include<bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

#define ll long long
#define endl '\n'
using namespace std;
using namespace __gnu_pbds;

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 2e5+7, P1 = 31, P2 = 37, mod= 1e9 + 7;
void doWork() {
    int n,m,k;
    cin >> n >> m >> k;
    if ( k > min(n,m))
        cout << "Impossible\n";
    else
    {
        cout << "Possible\n";
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < m; ++j) {
                if ( i == j && k)
                {
                    k--;
                    cout << '*';
                }
                else
                    cout << '.';
            }
            cout << endl;
        }
    }
}


int main() {
    ios::sync_with_stdio(false);
    cout.tie(nullptr);
    cin.tie(nullptr);
//    freopen("bisector.in","r",stdin);
//    freopen("bisector.out","w",stdout);
    int t = 1;
    // cout << primes.size() << endl;
    //cin >> t;
    while (t--) {
        doWork();
    }
    return 0;
}