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No
 No
 No
 Yes
 Yes
 No
 Yes
 Yes
 Yes
 No
 Yes
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 Yes
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 No
 No
 No

import sys
sys_in = sys.stdin


def read_ints():
    return map(lambda x: int(x), sys_in.readline().split())


def read_int():
    return int(sys_in.readline())

N, M = read_ints()

grid = []
for i in range(N):
    line = sys_in.readline().strip()
    grid.append(list(line))


for i in range(N):
    selected_cols = set()
    for j in range(M):
        if grid[i][j] == "#":
            selected_cols.add(j)
            grid[i][j] = "."
    for c in selected_cols:
        for i2 in range(i+1, N):
            if grid[i2][c] == "#":
                for j2 in range(M):
                    if j2 in selected_cols:
                        if grid[i2][j2] == ".":
                            sys.stdout.write("No\n")
                            exit(0)
                    else:
                        if grid[i2][j2] == "#":
                            sys.stdout.write("No\n")
                            exit(0)
                    grid[i2][j2] = "."
                grid[i2][c] = "."
sys.stdout.write("Yes\n")
