#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------


int H,W,K;
string S[1010101];
vector<ll> dp[1010101],dp2[1010101];
const ll mo=998244353;

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>H>>W>>K;
	if(H<=W) {
		FOR(y,H) cin>>S[y];
	}
	else {
		FOR(y,H) {
			cin>>s;
			FOR(x,W) S[x]+=s[x];
		}
		swap(H,W);
	}
	FOR(y,H+2) dp[y].resize(W+2),dp2[y].resize(W+2);
	dp[1][1]=1;
	
	FOR(y,H) FOR(x,W) {
		dp2[y+1][x+1]=dp2[y+1][x];
		
		if(S[y][x]=='.') {
			for(int y2=y;y2>=max(0,y-K);y2--) {
				dp[y+1][x+1]+=dp2[y2+1][x+1]+mo-dp2[y2+1][max(x-(K-(y-y2)),0)];
			}
			dp[y+1][x+1]%=mo;
			(dp2[y+1][x+1]+=dp[y+1][x+1])%=mo;
		}
		
	}
	cout<<dp[H][W]<<endl;
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}