h,m=map(int,input().split(':'))
z=zfill()
s=str
if m + 5 >=60:
    m = m - 55
    if h + 1 > 23:
        h = "00"
        print(h+":"+s(m).z(2))
    else:
        print(s(h+1).z(2)+":"+s(m).z())
else:
    print(s(h).z(2)+":"+s(m+5).z(2))