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

#define el '\n'
#define FIO ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;
typedef complex<ld> pt;
typedef unsigned long long ull;

template<typename T, typename X>
using hashTable = gp_hash_table<T, X>;
template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

// mt19937_64 for long long
mt19937 rng(std::chrono::system_clock::now().time_since_epoch().count());

void doWork()
{
    int n, m, k;
    cin >> n >> m >> k;
    if(k > min(n, m))
        cout << "Impossible";
    else
    {
        vector<vector<char>> grid(n, vector<char>(m, '.'));
        for(int i = 0; i < min({k, n, m}); i++)
            grid[i][i] = '*';

        cout << "Possible\n";
        for(int i = 0; i < n; i++, cout << '\n')
            for(int j = 0; j < m; j++)
                cout << grid[i][j];
    }
}

signed main()
{
    FIO
    int T = 1;
//    cin >> T;
    for(int i = 1; i <= T; i++)
        doWork();
}