R,G,B = map(int,input().split())
high = 10**7+1
low = 0
while high-low>1:
    mid = (high+low)//2
    x,y,z = R,G,B
    x -= mid
    y -= mid
    z -= mid
    if x<0 and y<0 and z<0:
        high = mid
        continue
    x,y,z = sorted([x,y,z])
    if y>=0:
        cnt = y//2+z//2
        if x+cnt>=0:
            low = mid
            continue
        high = mid
        continue
    else:
        if x+y+z//2>=0:
            low = mid
            continue
        high = mid
        continue
print(low)