#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
#define pll pair <ll,ll>
#define fi first
#define se second
#define sz(a) (ll((a).size()))
#define BIT(mask,i) (((mask) >> (i))&1LL)
#define MASK(i) (1LL << (i))
#define MP make_pair
ll ptr=0;
const ll MAXN=1000;
ll row[MAXN+100][MAXN+100],col[MAXN+100][MAXN+100];
ll timeDFS;
stack <ll> s;
ll sz_comp;
ll in[MAXN*MAXN+100],out[MAXN*MAXN+100],low[MAXN*MAXN+100],comp[MAXN*MAXN+100];
bool deleted[MAXN*MAXN+100];
ll comp_out[MAXN*MAXN+100];
vector <ll> g[MAXN*MAXN+100];
vector <ll> comp_g[MAXN*MAXN+100];
ll order_comp[MAXN*MAXN+100];
void dfs(ll u){
    in[u] = low[u] = ++timeDFS;
    s.push(u);
    for (auto v:g[u]){
        if (!in[v]){
            dfs(v);
            low[u] = min(low[u],low[v]);
        }
        else{
            if (!deleted[v])low[u] = min(low[u],in[v]);
        }
    }
    out[u] = timeDFS;
    if (low[u]==in[u]){
        sz_comp++;
        while (s.top()!=u){
            comp[s.top()]=sz_comp;
            deleted[s.top()]=1;
            s.pop();
        }
        comp[s.top()]=sz_comp;
        deleted[s.top()]=1;
        s.pop();
    }

}
int yellowblue(int n, int m, std::vector<std::string> s)
{
    for (ll i = 0;i < n;i ++){
        ll last = -1;
        for (ll j = 0;j <= m;j ++){
            if (j == m || s[i][j]=='#' ){
                if (j-last>1){
                    ll tmp=++ptr;
                    for (ll k = last+1;k < j;k ++){
                        row[i][k] = tmp;
                    }
                }
                last=j;
            }
        }
    }
    for (ll j = 0;j < m;j ++){
        ll last = -1;
        for (ll i = 0;i <= n;i ++){
            if (i==n||s[i][j]=='#'){
                if (i-last>1){
                    ll tmp =++ptr;
                    for (ll k = last+1;k < i;k ++){
                        col[k][j] = tmp;
                    }
                }
                last=i;
            }
        }
    }
    for (ll i = 0;i < n;i ++){
        ll last = -1;
        for (ll j = 0;j <= m;j ++){
            if (j == m || s[i][j]=='#'){
                if (j-last>1){
                    g[row[i][last+1]].push_back(col[i][last+1]);
                    g[row[i][j-1]].push_back(col[i][j-1]);
                }
                last=j;
            }
        }
    }
    for (ll j = 0;j < m;j ++){
        ll last = -1;
        for (ll i = 0;i <= n;i ++){
            if (i==n||s[i][j]=='#'){
                if (i-last>1){
                    g[col[last+1][j]].push_back(row[last+1][j]);
                    g[col[i-1][j]].push_back(row[i-1][j]);
                }
                last=i;
            }
        }
    }
//    for (ll i = 0;i < n;i ++){
//        for (ll j = 0;j < m;j ++){
//            cout<<row[i][j];
//        }
//        cout<<'\n';
//    }
//    cout<<'\n';
//    for (ll i = 0;i < n;i ++){
//        for (ll j = 0;j < m;j ++){
//            cout<<col[i][j];
//        }
//        cout<<'\n';
//    }
//    cout<<'\n';
//    for (ll i = 1;i <= ptr;i ++){
//        for (auto v:g[i]){
//            cout<<i<<' '<<v<<endl;
//        }
//    }
    for (ll i = 1;i <= ptr;i ++)if (!in[i])dfs(i);
//    for (ll i = 1;i <= ptr;i ++)cout<<i<<' '<<in[i]<<' '<<low[i]<<endl;
//    for (ll i = 1;i <= ptr;i ++)cout<<comp[i]<<' ';
//    cout<<endl;
    for (ll i = 1;i <= ptr;i ++){
        comp_out[comp[i]] = max(comp_out[comp[i]],out[i]);
        for (auto v:g[i]){
            comp_g[comp[i]].push_back(comp[v]);
        }
    }
    iota(order_comp+1,order_comp+1+sz_comp,1);
    sort(order_comp+1,order_comp+1+sz_comp,[&](ll x,ll y){return comp_out[x]>comp_out[y];});
    bool ok = 1;
    for (ll i = 1;i + 1 <= sz_comp;i ++){
        bool fail = 1;
        for (auto v:comp_g[order_comp[i]]){
            if (v==order_comp[i+1])fail = 0;
        }
        if (fail)ok=0;
    }
	return ok;
//return 1;
}