time=input()
t=time.split(":")
minute=int(t[1])+5
if minute<60:
    t[1]='{0:02d}'.format(minute)
else:
    hour=int(t[0])+1
    if hour<24:
        t[0]='{0:02d}'.format(hour)
    else:
        t[0]='{0:02d}'.format(0)
    t[1]='{0:02d}'.format(minute-60)
print(t[0]+':'+t[1])