Tontti

import java.util.*;
public class Puut {
	public static void main(String[] args) {
		IO io = new IO();
	
		int n, m, x;
		n = io.nextInt();
		m = io.nextInt();
		x = io.nextInt();
		
		int a = 0;
		
		long k[][][] = new long[n+1][m+1][4];
		for (int i = 1; i <= n; i++) {
			char[] r = io.next().toCharArray();
			for (int j = 1; j <= m; j++) {
				k[i][j][0] = k[i][j][1] = r[j-1] == '*' ? (long)1 : (long)0;
				if (k[i][j][0] == x) a++;
			}
		}
		
		l: for (int s = 2; s <= Math.min(n,m); s++) {
			for (int X = 1; X <= m; X++) {
				for (int Y = 1; Y <= n; Y++) {
					int nyk = 1+(s+2)%3;
					int ed = 1+(s+1)%3;
					int ed2 = 1+(s+0)%3;
					k[Y][X][nyk] = 0;
					if (X >= s && Y >= s) {
						k[Y][X][nyk] = k[Y][X][0];
						long t = s > 2 ? k[Y-1][X-1][ed2] : 0;
						long z = k[Y-s+1][X-s+1][0];
						long p = k[Y-1][X][ed];
						long q = k[Y][X-1][ed];
						
						//io.println("(" + X + ", " + Y + "; " + nyk + ", " + ed + ")[" + s + "] = " +
						//	k[Y][X][nyk] + " + " + p + " + " + q + " - " + t + " + " + z + " = " +
						//	(k[Y][X][nyk]+p+q-t+z));
						k[Y][X][nyk] += p + q - t + z;
					}
					if (k[Y][X][nyk] > 10*x) break l;
					if (k[Y][X][nyk] == x) {
						a++;
					}
				}
			}
		}
		
		io.println(a);
		
		io.close();
	}
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 7

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 8

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 9

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 10

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED