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 Yes
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 No

def run():
    h, w = (int(x) for x in input().split())

    g = []
    for _ in range(h):
        g.append(input())

    rows_tkn = [False] * h

    for i in range(h):
        if rows_tkn[i]:
            continue
        rows_tkn[i] = True

        curr_row = g[i]
        col_i = [i for i,x in enumerate(curr_row) if x == '#']
        # col_i = []
        # for ii, x in enumerate(curr_row):
        #     if x == '#':
        #         col_i.append(ii)
        if len(col_i) == 0:
            continue


        cols = [''.join([g[_][ind] for _ in range(h)]) for ind in col_i]
        # cols = []
        # for ii in col_i:
        #     _col = []
        #     for _ in range(h):
        #         _col.append(g[_][ii])
        #     _col = ''.join(_col)
        #     cols.append(_col)
        curr_col = cols[0]

        for cccc in cols:
            if cccc != curr_col:
                return False

        rows = [curr_row]
        for ii, x in enumerate(curr_col):
            if x == '#':
                rows.append(g[ii])
                rows_tkn[ii] = True

        for rrrr in rows:
            if rrrr != curr_row:
                return False

    return True
print('Yes' if run() else 'No')