#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <stack>
using namespace std;
typedef long long ll;
const int maxn = 222;
const int maxk = 55;
char mat[maxn][maxn];
int L[maxn][maxn][maxk];
int R[maxn][maxn][maxk];
int up[maxn][maxn][maxk];
int down[maxn][maxn][maxk];
int rows[maxn][maxn][maxk];
int cols[maxn][maxn][maxk];
int main() {
    ios_base::sync_with_stdio(false);
    int n, m, k;
    cin >> n >> m >> k;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            cin >> mat[i][j];
        }
    }
    
    for(int x = 0; x <= k; x++) {
        for(int i = 0; i < n; i++) {
            for(int j = 0; j < m; j++) {
                int tmp_x = x;
                if(mat[i][j] == '*') {
                    tmp_x--;
                }
                
                if(tmp_x < 0) {
                    up[i][j][x] = 0;
                }
                else {
                    up[i][j][x] = 1;
                    if(i > 0) {
                        up[i][j][x] += up[i - 1][j][tmp_x];
                    }
                }
            }
        }
    }
    for(int x = 0; x <= k; x++) {
        for(int i = n - 1; i >= 0; i--) {
            for(int j = m - 1; j >= 0; j--) {
                int tmp_x = x;
                if(mat[i][j] == '*') {
                    tmp_x--;
                }
                if(tmp_x < 0) {
                    down[i][j][x] = 0;
                }
                else {
                    down[i][j][x] = 1;
                    if(i + 1 < n) {
                        down[i][j][x] += down[i + 1][j][tmp_x];
                    }
                }
            }
        }
    }
    for(int x = 0; x <= k; x++) {
        for(int i = 0; i < n; i++) {
            for(int j = 0; j < m; j++) {
                int tmp_x = x;
                if(mat[i][j] == '*') {
                    tmp_x--;
                }
                if(tmp_x < 0) {
                    L[i][j][x] = 0;
                }
                else {
                    L[i][j][x] = 1;
                    if(j > 0) {
                        L[i][j][x] += L[i][j - 1][tmp_x];
                    }
                }
            }
        }
    }
    for(int x = 0; x <= k; x++) {
        for(int i = n - 1; i >= 0; i--) {
            for(int j = m - 1; j >= 0; j--) {
                int tmp_x = x;
                if(mat[i][j] == '*') {
                    tmp_x--;
                }
                if(tmp_x < 0) {
                    R[i][j][x] = 0;
                }
                else {
                    R[i][j][x] = 1;
                    if(j + 1 < m) {
                        R[i][j][x] += R[i][j + 1][tmp_x];
                    }
                }
            }
        }
    }
    
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            for(int x = 0; x <= k; x++) {
                rows[i][j][x] = 0;
                int tmp_x = x;
                if(mat[i][j] == '*') {
                    tmp_x--;
                }
                if(tmp_x >= 0) {
                    for(int y = 0; y <= tmp_x; y++) {
                        int tmp_y = tmp_x - y;
                        int sum = 1;
                        if(i + 1 < n) {
                            sum += down[i + 1][j][tmp_y];
                        }
                        if(i > 0) {
                            sum += up[i - 1][j][y];
                        }
                        rows[i][j][x] = max(rows[i][j][x], sum);
                    }
                }
            }
        }
    }
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            for(int x = 0; x <= k; x++) {
                cols[i][j][x] = 0;
                int tmp_x = x;
                if(mat[i][j] == '*') {
                    tmp_x--;
                }
                if(tmp_x >= 0) {
                    for(int y = 0; y <= tmp_x; y++) {
                        int tmp_y = tmp_x - y;
                        int sum = 1;
                        if(j + 1 < m) {
                            sum += R[i][j + 1][y];
                        }
                        if(j > 0) {
                            sum += R[i][j - 1][tmp_y];
                        }
                        cols[i][j][x] = max(cols[i][j][x], sum);
                    }
                }
            }
        }
    }
    int result= 0;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            int tmp_x = k;
            int obstacle = 0;
            if(mat[i][j] == '*') {
                tmp_x--;
                obstacle = 1;
            }
            if(tmp_x >= 0) {
                for(int x = 0; x <= tmp_x; x++) {
                    int y = tmp_x - x;
                    int r_tmp = x + obstacle;
                    int c_tmp = y + obstacle;
                    result = max(result, rows[i][j][r_tmp] + cols[i][j][c_tmp] - 1);
                }
            }
        }
    }
    cout << result - 1 << endl;
    return 0;
}