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

def check(n):
    left = 0
    shrt = 0
    for i in (R,G,B):
        if i >= n:
            left += (i-n)//2
        else:
            shrt += n-i
    return left >= shrt

total = 0
for i in range(24,-1,-1):
    if check(total+pow(2,i)):
        total += pow(2,i)
print(total)