#include <iostream>
#include<bits/stdc++.h>
#define int long long
#define FIO ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

using namespace std;

const int N = 1e5 + 20, M = 1e6 + 5;
const int mod = 998244353;
void debug() {
#ifdef Debug
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
#endif
}

void getAnswer()
{   
    int a, b, k;
    cin >> a >> b >> k;
    if(k > min(a,b))
        cout << "Impossible\n";
    else
    {
        cout << "Possible\n";
        for(int i = 0;i < a;++i)
        {
            for(int j = 0;j < b;++j)
            {
                if(i == j)
                    cout << '*';
                else
                    cout << ".";
            }
            cout << "\n";
        }
    }
}
signed main()
{
    FIO
    debug();
    int t = 1;
    //cin >> t;
    while(t--)
        getAnswer();
    return 0;

}