C = sorted( list( map(int, input().split())) )
ANS = 0
ANS = C[0]

C[1] -= C[0]
C[2] -= C[0]
C[0] = 0

a, b = C[1], C[2]

while(True):
    if a >= 1 and b >=3:
        ANS += 1
    else:
        break
    a -= 1
    b -= 3
    aa = min(a, b)
    bb = max(a, b)
    a, b = aa, bb

ANS += b//5


print(ANS)