#pragma GCC optimize(2)

#pragma GCC optimize(3)

#pragma GCC optimize(4)

#include<bits/stdc++.h>

using namespace std;

#define y1 y11

#define fi first

#define se second

#define pi acos(-1.0)

#define LL long long

//#define mp make_pair

#define pb emplace_back

#define ls rt<<1, l, m

#define rs rt<<1|1, m+1, r

#define ULL unsigned LL

#define pll pair<LL, LL>

#define pli pair<LL, int>

#define pii pair<int, int>

#define piii pair<pii, int>

#define pdd pair<double, double>

#define mem(a, b) memset(a, b, sizeof(a))

#define debug(x) cerr << #x << " = " << x << "\n";

#define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);

//head

 

const int N = , M = ;

int n, m, ST, id1[N][N], id2[N][N], cnt, x, y;

pii st[M], ed[M];

bool can[M][M];

char s[N][N];

namespace two_sat {

    int dfn[M*], low[M*], cnt, stk[M*], top, cmp[M*], tot, n;

    bool vis[M*];

    vector<int> g[M*];

    void init(int sz) {

        n = sz;

    }

    void add(int u, int v) {

        g[u].pb(v);

    }

    void tarjan(int u) {

        dfn[u] = low[u] = ++cnt;

        stk[++top] = u;

        vis[u] = true;

        for (int v : g[u]) {

            if(!dfn[v]) tarjan(v), low[u] = min(low[u], low[v]);

            else if(vis[v]) low[u] = min(low[u], dfn[v]);

        }

        if(dfn[u] == low[u]) {

            cmp[u] = ++tot;

            while(stk[top] != u) cmp[stk[top]] = tot, vis[stk[top--]] = false;

            vis[stk[top--]] = false;

        }

    }

    bool ck() {

        for (int i = ; i <= *n; ++i) if(!dfn[i]) tarjan(i);

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

            if(cmp[i] == cmp[i+n]) return false;

        }

        return true;

    }

}

void dfs(int u) {

    can[ST][u] = true;

    int v = id1[st[u].fi][st[u].se]^id2[st[u].fi][st[u].se]^u;

    if(!can[ST][v]) dfs(v);

    v = id1[ed[u].fi][ed[u].se]^id2[ed[u].fi][ed[u].se]^u;

    if(!can[ST][v]) dfs(v);

}

int main() {

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

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

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

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

            if(s[i][j] == 'O') x = i, y = j;

            if(s[i][j] != '#') {

                if(j ==  || s[i][j-] == '#') st[++cnt] = {i, j};

                id1[i][j] = cnt;

                if(j == m || s[i][j+] == '#') ed[cnt] = {i, j};

            }

        }

    }

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

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

            if(s[i][j] != '#') {

                if(i ==  || s[i-][j] == '#') st[++cnt] = {i, j};

                id2[i][j] = cnt;

                if(i == n || s[i+][j] == '#') ed[cnt] = {i, j};

            }

        }

    }

    two_sat::init(cnt);

    for (int i = ; i <= cnt; ++i) {

        ST = i;

        dfs(ST);

    }

    for (int i = ; i <= cnt; ++i) if(!can[id1[x][y]][i] && !can[id2[x][y]][i]) two_sat::add(i, i+cnt);

    for (int i = ; i <= cnt; ++i) {

        for (int j = i+; j <= cnt; ++j) {

            if(!can[i][j] && !can[j][i]) two_sat::add(i, cnt+j), two_sat::add(j, cnt+i);

        }

    }

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

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

            if(s[i][j] == '*') {

                two_sat::add(id1[i][j]+cnt, id2[i][j]);

                two_sat::add(id2[i][j]+cnt, id1[i][j]);

            }

        }

    }

    if(two_sat::ck()) printf("YES\n");

    else printf("NO\n");

    return ;

}