import math as mh
a=input().split()
s=int(a[0])
v=int(a[1])
Time=mh.ceil(s/v)+10
if Time>480:
    Time=1440-(Time-480)
else:
    Time=480-Time
st=str(Time//60//10)+str(Time//60%10)+":"+str(Time%60//10)+str(Time%60%10)
print(st)

错误：Runtime Error. Program exited with code 1.