while True:

try:

a, b, n = [int(i) for i in input().split()]

k = a*(10**n)//b

result, m = divmod(k, 10**n)

m = str(m)

if len(m) < n:

for i in range(n-len(m)):

m = m + '0'

print(str(result) + '.' + m)

except:

break

for i in range(n-len(m)):

m = m + '0'

答案小於0.1時會出錯

'0'要放在前面，所以m = m + '0'可以改成m = '0' + m，或者是不用for迴圈，改成

m = '0' * (n-len(m)) + m