Untitled

#include <bits/stdc++.h>
#define endl '\n'
#define maxn 15

using namespace std;
int a[maxn][maxn],m,n,s,d;
double sum = 0,ans = -10e9;
void inp(){
    cin >> m >> n >> s;
    for (int i = 1; i<=m; i++)
    for (int j = 1; j<=n; j++)
         cin >> a[i][j];
}
void solve(){
        for (int i = 1; i<=m; i++)
        for (int j = 1; j<=n; j++)
        for (int h1 = 1; h1<=m; h1++)
        for (int c1 = 1; c1<=n; c1++){
             d = 0; sum = 0;
        for (int h = i; h<=h1; h++)
        for (int c = j; c<=c1; c++){
             d++;
             sum += a[h][c];
        }
             if (d >= s) ans = max(ans,sum/d);
        }
        cout << setprecision(2) << fixed << ans;
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if(fopen("bai32.inp","r")){
        freopen("bai32.inp","r",stdin);
    }
    inp();
    solve();
}