a,b=input().split()
a=int(a)
b=int(b)
c=a/b
if round(c)<a/b:
    c=round(c)+1
else:
    c=round(c)
#print(c)
m=60-c%60-10
n=7-(c-c%60)/60
n=round(n)
#print(n,m)
if(n<0):
    print(24+n,sep="",end="")
else:
    print("0",n,sep="",end="")
if(m<10):
    print(":","0",m,sep="",end="")
else:
    print(":",m,sep="",end="")