import sequtils,strutils,math
var
    R,G,B : int
    cnt = 0
    m,M,n : int
    
(R,G,B) = stdin.readline.split.map(parseInt)
m = min(@[R,G,B])
R -= m
G -= m
B -= m
cnt += m
m = 0
M = max(@[R, G, B])

var A = [R,G,B]
proc test(x : int):bool =
    var fcnt : int
    for a in A:
        fcnt += min(a, x)
        fcnt += max((a - x) div 2, 0)
    result = (fcnt >= x * 3)
        
while m != M:
    n = (m + M + 2) div 2
    if test(n):
        m = n
    else:
        M = n - 1

echo m + cnt