mcnug(largest no.)

x = [1,2,3,4,5]
candidate = 6
for a in range (0, 100):
    for b in range (0, 100):
        for c in range (0, 100):
            tot = 6*a+9*b+20*c
            if candidate != tot:
                x.append(candidate)
            candidate = candidate +1
print x[-1]