R, G, B = map(int, input().split())

sum_rgb = R + G + B
low = 0
high = sum_rgb // 3
best = 0

while low <= high:
    mid = (low + high) // 2
    # Calculate deficits
    d_r = max(mid - R, 0)
    d_g = max(mid - G, 0)
    d_b = max(mid - B, 0)
    total_deficit = d_r + d_g + d_b
    
    # Calculate surplus
    s_r = max(R - mid, 0)
    s_g = max(G - mid, 0)
    s_b = max(B - mid, 0)
    total_surplus = (s_r // 2) + (s_g // 2) + (s_b // 2)
    
    if total_deficit <= total_surplus:
        best = mid
        low = mid + 1
    else:
        high = mid - 1

print(best)