#include <cmath>

#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

#define maxn 905

#define INF 0x7ffffff

struct NodeType {

    int x,y,hi;

};

struct NodeType ai[maxn];

int n,m,cnt=,tot,map[maxn][maxn],s,t,que[maxn*maxn*],tott,d;

int head[maxn],deep[maxn],F[maxn*maxn*],E[maxn*maxn*],V[maxn*maxn*];

inline void edge_add(int u,int v,int f)

{

    E[++cnt]=head[u],V[cnt]=v,F[cnt]=f,head[u]=cnt;

    E[++cnt]=head[v],V[cnt]=u,F[cnt]=,head[v]=cnt;

}

bool bfs()

{

    for(int i=s;i<=t;i++) deep[i]=-;

    int h=,tail=;que[h]=s,deep[s]=;

    while(h<tail)

    {

        int now=que[h++];

        for(int i=head[now];i;i=E[i])

        {

            if(deep[V[i]]<&&F[i]>)

            {

                deep[V[i]]=deep[now]+;

                if(V[i]==t) return true;

                que[tail++]=V[i];

            }

        }

    }

    return false;

}

int flowing(int now,int flow)

{

    if(now==t||flow<=) return flow;

    int oldflow=;

    for(int i=head[now];i;i=E[i])

    {

        if(deep[V[i]]==deep[now]+&&F[i]>)

        {

            int pos=flowing(V[i],min(flow,F[i]));

            F[i]-=pos,F[i^]+=pos;

            flow-=pos,oldflow+=pos;

            if(flow==) return oldflow;

        }

    }

    if(oldflow==) deep[now]=-;

    return oldflow;

}

int main()

{

    scanf("%d%d%d",&n,&m,&d);

    char ch[];

    for(int i=;i<=n;i++)

    {

        scanf("%s",ch+);

        for(int j=;j<=m;j++)

        {

            if(ch[j]!='') ai[++tot].x=i,ai[tot].y=j,ai[tot].hi=ch[j]-'',map[i][j]=tot;

        }

    }

    t=tot*+;

    for(int i=;i<=tot;i++)

    {

        edge_add(i,i+tot,ai[i].hi);

        for(int j=;j<=tot;j++)

        {

            if(j==i) continue;

            if(abs(ai[i].x-ai[j].x)+abs(ai[i].y-ai[j].y)<=d) edge_add(i+tot,j,INF);

        }

        if(ai[i].x<=d||ai[i].y<=d||n-ai[i].x+<=d||m-ai[i].y+<=d) edge_add(i+tot,t,INF);

    }

    for(int i=;i<=n;i++)

    {

        scanf("%s",ch+);

        for(int j=;j<=m;j++) if(ch[j]=='L') edge_add(s,map[i][j],),tott++;

    }

    int ans=;

    while(bfs()) ans+=flowing(s,INF);

    cout<<tott-ans;

    return ;

}