s = list(map(int, input().split()))
s.sort()
total = s[0]
for i in range(3):
    s[i] -= total
while True:
    if s[0] == 0:
        if s[2]-s[1] < 3:
            z = s[1]//4
            total += z*2
            s[1] -= z*4
            s[2] -= z*4
        z = min((s[2]-s[1]+2)//2,s[2]//3)
        s[2] -= z*2
        s[0] += z
    if all(s[i] > 0 for i in range(3)):
        m = min(s)
        total += m
        for i in range(3):
            s[i] -= m
    s.sort()
    if (s[1]==1 and s[2]<3) or (s[1]==0 and s[2]<5) or (s[1]==2 and s[2]==2):
        break
    # print(total , s)
print(total)