#include <bits/stdc++.h>

#define R register
#define ll long long
#define sum(a, b, mod) (((a) + (b)) % mod)
#define meow(cat...) fprllf(stderr, cat)

const ll Max = 1e2 + 10;
const ll inf = 1e17;
const ll MaxN = 1e5 + 10;

struct edge
{
    ll next, to, flow;
} e[MaxN << 1];

char str[Max][Max];
ll row[Max][Max], col[Max][Max];
ll n, m, ans, s = 20001, t = 20002, cnt = 1;
ll now, head[MaxN], dep[MaxN], cur[MaxN];

void add(ll u, ll v, ll f)
{
    ++cnt;
    e[cnt].to = v;
    e[cnt].flow = f;
    e[cnt].next = head[u];
    head[u] = cnt;
} 

void add_edge(ll u, ll v, ll f) { add(u, v, f), add(v, u, 0); }

ll bfs()
{
    memset(dep, 0, sizeof(dep));
    memcpy(cur, head, sizeof(head));
    std::queue<ll> q; q.push(s), dep[s] = 1;
    while(!q.empty())
    {
        int u = q.front(); q.pop();
        for(int i = head[u]; i; i = e[i].next)
        {
            int v = e[i].to, c = e[i].flow;
            if(dep[v] || !c) continue;
            dep[v] = dep[u] + 1, q.push(v);
        }
    }
    return dep[t];
}

ll dinic(ll u, ll flow)
{
    if(u == t) return flow;
    ll rest = flow;
    for(int i = cur[u]; i && rest; i = e[i].next)
    {
        cur[u] = i; ll v = e[i].to, c = e[i].flow, k;
        if(dep[v] != dep[u] + 1 || !c) continue;
        k = dinic(v, std::min(rest, c));
        if(!k) dep[v] = -1;
        else e[i].flow -= k, e[i ^ 1].flow += k, rest -= k;
    }
    if(flow - rest < flow) dep[u] = -1;
    return flow - rest;
}

inline ll read()
{
    ll x = 0;
    char ch = getchar();
    while(ch > '9' || ch < '0')
        ch = getchar();
    while(ch <= '9' && ch >= '0') 
        x = (x << 1) + (x << 3) + (ch ^ 48), ch = getchar();
    return x;
}

void solve()
{
    ll now = 0;
    while(bfs())
        while((now = dinic(s, inf)))
            ans += now;
}

signed main()
{   
    n = read(), m = read();
    for(int i = 1; i <= n; i++)
        scanf("%s", str[i] + 1);
    for(int i = 1; i <= n; i++)
    {
        ++now, add_edge(s, now, 1);
        for(int j = 1; j <= m; j++)
        {
            if(str[i][j] == '#') 
                ++now, add_edge(s, now, 1);
            row[i][j] = now;
        }
    }
    for (int j = 1; j <= m; j++)
    {
        ++now, add_edge(now, t, 1);
        for (int i = 1; i <= n; i++)
        {
            if (str[i][j] == '#') 
                ++now, add_edge(now, t, 1);
            col[i][j] = now;
        }
    }
    // for(int i = 1; i <= n; i++)
    //     for(int j = 1; j <= m; j++)
    //         printf("%lld%c", row[i][j], " \n"[j == m]);
    // for (int i = 1; i <= n; i++)
    //     for (int j = 1; j <= m; j++)
    //         printf("%lld%c", col[i][j], " \n"[j == m]);
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= m; j++)
            if(str[i][j] == '*')
                add_edge(row[i][j], col[i][j], 1);
    solve(), printf("%lld\n", ans);
    return 0;
}