R, G, B = [int(i) for i in input().strip().split(" ")]
total = 0
m = 0

while True:
    if R * G * B != 0:
        m = min(R,G,B)
        R -= m
        G -= m
        B -= m
    total += m
    f, s, t = sorted([R,G,B], reverse=True)
    if s == t:
        if f < 5:
            break
        s = (f - f // 4) // 2
        t = s
        tmp = f - t - s 
        f = f//4 + tmp
    else:
        if f < 3:
            break
        if f - s > 1:
            t = (f-s) // 2
            f -= f - s - (f-s-t*2)
        else:
            t = (f//2)//2 + (s//2)//2
            f -= f // 2
            s -= s // 2
    R,G,B = f,s,t

print(total)