import sys


def kek(a):
    ryad = [0] * len(a)
    stolb = [0] * len(a[0])
    for i in range(len(a)):
        for j in range(len(a[i])):
            if a[i][j] == '*':
                ryad[i] += 1
                stolb[j] += 1
    maxRyad = max(ryad)
    maxStolb = max(stolb)
    ans = len(a) + len(a[0]) - maxRyad - maxStolb
    for i in range(len(ryad)):
        for j in range(len(stolb)):
            if ryad[i] == maxRyad and stolb[j] == maxStolb and a[i][j] == '.':
                ans -= 1
                return ans
    return ans

def YAMASHINATUTUTUT():
    inp = sys.stdin.read().split('\n')
    n = int(inp[0])
    ind = 0
    for i in range(n):
        ind += 1
        tn, tm = list(map(int, inp[ind].split()))
        answer = []
        for j in range(tn):
            ind += 1
            answer.append(inp[ind])
        print(kek(answer))

YAMASHINATUTUTUT()