n, m, d = list(map(int,input().split()))

ans = 2 * (n - d) * (m - 1) / (n ** 2)



if d == 0:

    ans /= 2



print(ans)
n, m, d = list(map(int,input().split()))

ans = 2 * (m - 1) * (n - d) / n ** 2

if d == 0:

    ans /= 2

print(ans)
n, m, d = list(map(int, input().split()))
ans = 2 * (n - d) * (m - 1) / (n**2)
if d == 0:
    ans /= 2
print(ans)

n, m, d = list(map(int, input().split()))
ans = 2 * (m - 1) * (n - d) / n**2
if d == 0:
    ans /= 2
print(ans)

-ans = 2 * (n - d) * (m - 1) / (n**2) +ans = 2 * (m - 1) * (n - d) / n**2