tanshin,choshin=map(int,input().split())

choshin_rad=choshin*6

if tanshin<12:
    tanshin_rad=tanshin*30+choshin_rad/12
else:
    tanshin_rad=(tanshin-12)*30+choshin_rad/12

if tanshin_rad>=choshin_rad:
    sabun=tanshin_rad-choshin_rad
else:
    sabun=360-(choshin_rad-tanshin_rad)

print(int(sabun/5.5*60) )