stn = [int(i) for i in input().split()]
stn.sort()
acc = 0
while stn[0] >= 1:
    stn[0] -= 1
    stn[1] -= 1
    stn[2] -= 1
    stn.sort()
    acc += 1
while stn[1] >= 1 and stn[2] >= 3:
    stn[1] -= 1
    stn[2] -= 3
    stn.sort()
    acc += 1
while stn[2] >= 5:
    stn[2] -= 5
    acc += 1    
print(acc)