845 B | 845 chars
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
# sys.setrecursionlimit(10**7)
BLANK = " "
# inp = input
inp = lambda : sys.stdin.readline().rstrip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def gcd(a, b): return gcd(b, a % b) if b > 0 else a
def lcm(a, b): return a * b // gcd(a, b)
def solve():
R, G, B = mii()
ans = 0
z = min(R, G, B)
ans += z
R -= z
G -= z
B -= z
ans += R // 3
R %= 3
ans += G // 3
G %= 3
ans += B // 3
B %= 3
l = [R, G, B]
if l.count(1) == 2:
ans += 1
else:
ans += (R + 1) // 2 + (G + 1) // 2 + (B + 1) // 2
p(ans)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()