A,B = map(int,input().split())
def clock(A,B,C):#A時B分C秒の時のradA,radB,radC
    radC = C*6
    radB = B*6+(radC/360)*6
    radA = (A%12)*30+(radB/360)*30
    return radA,radB,radC

radA,radB,radC = clock(A,B,0)
if radA < radB:
    d = radA+360-radB
else:
    d = radA-radB
ans = (d*120)/11
#d/(1/10-1/120)
print(int(ans))