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import java.util.*;

public class MysticalMosaic{
	public static void main(String[] args){
		Scanner reader = new Scanner(System.in);
		int m = reader.nextInt();
		int n = reader.nextInt();
		char[][] board = new char[m][n];
		int[] rowCount = new int[m];
		int[] colCount = new int[n];

		reader.nextLine();

		for (int i = 0; i < m; ++i){
			String curLine = reader.nextLine();

			for (int j = 0; j < n; ++j){
				board[i][j] = curLine.charAt(j);

				if (board[i][j] == '#'){
					rowCount[i]++;
					colCount[j]++;
				}
			}
		}

		Set<Integer> row = new HashSet<>();
		Set<Integer> col = new HashSet<>();
		int totalChanged = 0;

		for (int i = 0; i < m; ++i){
			if (rowCount[i] == 0 || row.contains(i)){
				continue;
			}
			row.add(i);

			for (int j = 0; j < n; ++j){
				if (board[i][j] == '#'){
					col.add(j);

					for (int k = 0; k < m; ++k){
						if (board[k][j] == '#'){
							if (rowCount[k] != rowCount[i]){
								System.out.println("No");
								return;
							} 

							row.add(k);
						}
					}
				}
			}
		}

		System.out.println("Yes");
	}
}