#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

#define INF 0x3f3f3f3f

#define maxn 2000005

int n,m,s,t,que[maxn],deep[maxn],toth,totl,F[maxn],cnt=;

int idh[][],idl[][],E[maxn],V[maxn],head[maxn];

char map[][];

bool if_[][];

inline bool bfs()

{

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

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

    while(h<tail)

    {

        now=que[h++];

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

        {

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

            {

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

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

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

            }

        }

    }

    return false;

}

inline int flowing(int now,int flow)

{

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

    int oldflow=,pos;

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

    {

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

        {

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

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

            if(!flow) return oldflow;

        }

    }

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

    return oldflow;

}

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;

}

int main()

{

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

    for(int i=;i<=n;i++) scanf("%s",map[i]+);

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

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

            if(map[i][v]=='*'&&!idh[i][v])

            {

                toth++;

                for(int l=v;l>&&map[i][l]!='#';l--)

                {

                    idh[i][l]=toth;

                    if(map[i][l]=='x') idh[i][l]=;

                }

                for(int r=v+;r<=m&&map[i][r]!='#';r++)

                {

                    idh[i][r]=toth;

                    if(map[i][r]=='x') idh[i][r]=;

                }

            }

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

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

            if(map[i][v]=='*'&&!idl[i][v])

            {

                totl++;

                for(int l=i;l>&&map[l][v]!='#';l--)

                {

                    idl[l][v]=totl;

                    if(map[l][v]=='x') idl[l][v]=;

                }

                for(int r=i+;r<=n&&map[r][v]!='#';r++)

                {

                    idl[r][v]=totl;

                    if(map[r][v]=='x') idl[r][v]=;

                }

            }

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

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

            if(idh[i][v]&&idl[i][v]&&!if_[idh[i][v]][idl[i][v]])

            {

                if_[idh[i][v]][idl[i][v]]=true;

                edge_add(idh[i][v],idl[i][v]+toth,);

            }

    s=,t=toth+totl+;

    for(int i=;i<=toth;i++) edge_add(s,i,);

    for(int i=;i<=totl;i++) edge_add(i+toth,t,);

    int ans=;

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

    cout<<ans;

    return ;

}