from scipy.optimize import linprog

for _ in range(int(input())):
    n, m = map(int, input().split())
    a = [list(map(float, input().split())) for _ in range(n)]

    r = linprog(
        [0] * n + [-1],
        [[-a[i][j] for i in range(n)] + [1] for j in range(m)],
        [0] * m,
        [[1] * n + [0]],
        [1],
        bounds=[(0, None)] * n + [(None, None)]
    )

    print(r.x[-1])