#include <stdio.h>
#include <stdlib.h>

const int Mod = 998244353;

int main()
{
	int i, j, H, W, K;
	char **c, **c_tmp;
	scanf("%d %d %d", &H, &W, &K);
	c_tmp = (char**)malloc(sizeof(char*) * (H + 2));
	for (i = 1; i <= H; i++) {
		c_tmp[i] = (char*)malloc(sizeof(char) * (W + 2));
		scanf("%s", &(c_tmp[i][1]));
	}
	if (H <= W) {
		W += K;
		c = (char**)malloc(sizeof(char*) * (H + 2));
		for (i = 0; i <= H + 1; i++) {
			c[i] = (char*)malloc(sizeof(char) * (W + 2));
			for (j = 0; j <= W + 1; j++) c[i][j] = 0;
		}
		for (i = 1; i <= H; i++) for (j = K + 1; j <= W; j++) c[i][j] = c_tmp[i][j-K];
	} else {
		H ^= W;
		W ^= H;
		H ^= W;
		W += K;
		c = (char**)malloc(sizeof(char*) * (H + 2));
		for (i = 0; i <= H + 1; i++) {
			c[i] = (char*)malloc(sizeof(char) * (W + 2));
			for (j = 0; j <= W + 1; j++) c[i][j] = 0;
		}
		for (i = 1; i <= H; i++) for (j = K + 1; j <= W; j++) c[i][j] = c_tmp[j-K][i];
	}
	
	int tmp, **dp, **dp_sum_add, **dp_sum_sub;
	dp = (int**)malloc(sizeof(int*) * (H + 2));
	dp_sum_add = (int**)malloc(sizeof(int*) * (H + 2));
	dp_sum_sub = (int**)malloc(sizeof(int*) * (H + 2));
	for (i = 0; i <= H + 1; i++) {
		dp[i] = (int*)malloc(sizeof(int) * (W + 2));
		dp_sum_add[i] = (int*)malloc(sizeof(int) * (W + 2));
		dp_sum_sub[i] = (int*)malloc(sizeof(int) * (W + 2));
	}
	for (i = 0; i <= H + 1; i++) {
		for (j = 0; j <= W + 1; j++) {
			dp[i][j] = 0;
			dp_sum_add[i][j] = 0;
			dp_sum_sub[i][j] = 0;
		}
	}
	dp[1][K+1] = 1;
	dp_sum_add[1][K+1] = 1;
	dp_sum_sub[1][K+1] = 1;
	for (i = 1, j = K + 2, tmp = 1; 1; j++) {
		if (j > W) {
			i++;
			if (i > H) break;
			j = 0;
			tmp = 0;
		}
		tmp += dp_sum_add[i-1][j];
		if (j >= K + 1) tmp -= dp_sum_sub[i][j-K-1];
		if (tmp >= Mod) tmp -= Mod;
		else if (tmp < 0) tmp += Mod;
	
		if (c[i][j] == '.') dp[i][j] = tmp;
		else dp[i][j] = 0;
		dp_sum_add[i][j] = dp_sum_add[i-1][j] + dp[i][j];
		if (i - K >= 1) dp_sum_add[i][j] -= dp[i-K][j];
		if (dp_sum_add[i][j] >= Mod) dp_sum_add[i][j] -= Mod;
		else if (dp_sum_add[i][j] < 0) dp_sum_add[i][j] += Mod;
		dp_sum_sub[i][j] = dp_sum_sub[i-1][j+1] + dp[i][j];
		if (i - K - 1 >= 1 && j + K + 1 <= W) dp_sum_sub[i][j] -= dp[i-K-1][j+K+1];
		if (dp_sum_sub[i][j] >= Mod) dp_sum_sub[i][j] -= Mod;
		else if (dp_sum_sub[i][j] < 0) dp_sum_sub[i][j] += Mod;

		tmp += dp[i][j];
		if (tmp >= Mod) tmp -= Mod;
	}
	printf("%d\n", dp[H][W]);
	fflush(stdout);
	return 0;
}