#include <bits/stdc++.h>

//#define TASK "lca"

#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define F first
#define S second
#define pb push_back
#define int long long
#define pii pair<int, int>

typedef long long ll;
typedef long double ld;

using namespace std;

const int INF = 1e18;
const int MAXN = 30;
const double EPS = 1e-3;

ll power(ll x, ll n, ll mod = 1e18 + 7) {
    if (n == 0) return 1ll;
    if (n & 1ll) return power(x, n - 1ll, mod) * x % mod;
    ll tmp = power(x, n >> 1ll, mod);
    return (tmp * tmp) % mod;
}

ll gcd(ll a, ll b) {
    if (b == 0) return a;
    return gcd (b, a % b);
}

ll lcm(ll a, ll b) {
    return a / gcd(a, b) * b;
}

bool check(int i, int j, vector<vector<int>> &g) {
    for (int k = 0; k < g[i].size(); k++) {
        if (g[i][k] != g[j][k]) return 0;
    }
    return 1;
}

signed main() {
#ifndef LOCAL
#ifdef TASK
    freopen(TASK".in", "r", stdin);
    freopen(TASK".out", "w", stdout);
#endif
#endif
#ifdef LOCAL
    //freopen("/Users/alekseygolub/Desktop/с++/ABS/ABS/input.txt", "r", stdin);
#endif
    iostream::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    srand(924653523);
    // == SOLUTION == //
    int n, m;
    cin >> n >> m;
    vector<vector<int>> g(n, vector<int> (m, 0));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            char c;
            cin >> c;
            g[i][j] = bool(c == '#');
        }
    }
    vector<bool> used(n, 0);
    for (int i = 0; i < n; i++) {
        if (1) {
            for (int j = 0; j < m; j++) {
                if (g[i][j]) {
                    for (int k = 0; k < n; k++) {
                        if (g[k][j]) {
                            if (!check(i, k, g)) {
                                cout << "No\n";
                                return 0;
                            }
                            used[i] = used[k] = 1;
                        }
                    }
                }
            }
        }
    }
    cout << "Yes\n";
    return 0;

}