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

ans = min(r,g,b)
r,g,b = r-ans,g-ans,b-ans

A = [r,g,b]
A.sort()

while True:
    maxim = A[2]
    minus = (maxim+1)//2
    plus = minus//2
    
    A[2] -= minus
    A[0] += plus
    
    tmp = min(A)
    if min(A) == 0:
        break
    ans += tmp
    for i in range(3):
        A[i] -= tmp
        
    A.sort()
    
print(ans)