#include<bits/stdc++.h>

#define rep(i,a,b) for(int i=a;i<=b;i++)

using namespace std;

const int maxn=;

const int Mod=;

int dp[maxn][maxn],same[maxn][maxn];

int sum1[maxn][maxn],sum2[maxn][maxn];

char c[maxn][maxn];

int main()

{

    int T,N,M,K,ans;

    scanf("%d",&T);

    while(T--){

        scanf("%d%d%d",&N,&M,&K);

        rep(i,,N) scanf("%s",c[i]+);

        rep(i,,M) {

            dp[][i]=;

            same[][i]=(i!=&&c[][i]==c[][i-]);

            sum1[][i]=sum1[][i-]+dp[][i];

            sum2[][i]=sum2[][i-]+same[][i];

        }

        rep(i,,N){

            rep(j,,M) {

                dp[i][j]=((sum1[i-][min(M,j+K)]-sum1[i-][max(,j-K-)])%Mod+Mod)%Mod-((sum2[i-][min(M,j+K)]-sum2[i-][max(,j-K)])%Mod+Mod)%Mod;

                if(dp[i][j]<) dp[i][j]+=Mod;

                if(j==||c[i][j]!=c[i][j-]) same[i][j]=;

                else same[i][j]=((sum1[i-][min(M,j+K-)]-sum1[i-][max(,j-K-)])%Mod+Mod)%Mod-((sum2[i-][min(M,j+K-)]-sum2[i-][max(,j-K)])%Mod+Mod)%Mod;

                if(same[i][j]<) same[i][j]+=Mod;

                sum1[i][j]=(sum1[i][j-]+dp[i][j])%Mod;

                sum2[i][j]=(sum2[i][j-]+same[i][j])%Mod;

            }

        }

        ans=;

        rep(i,,M) ans=((ans+(dp[N][i]-same[N][i])%Mod)%Mod+Mod)%Mod;

        printf("%d\n",ans);

    }

    return ;

}