r,b,g=map(int,input().split())


def  cal(x):
    fusoku=0
    yojou=0
    for i in [r,b,g]:
        if i - x < 0:
            fusoku -= i - x
        else:
            yojou += (i - x)//2
    if fusoku <= yojou:
        return True
    else:
        return False
low = 0
high = 10**7

while  high-low > 1:
    mid = (low+high)//2
    tt = cal(mid)
    #print(tt,mid,low,high)
    if tt:
        low = mid 
    else:
        high = mid
        
print(low)