MOD = 10 ** 9 + 7
INF = 10 ** 20
import sys
input = sys.stdin.readline
sys.setrecursionlimit(100000000)
from collections import defaultdict
dy = (-1,0,1,0)
dx = (0,1,0,-1)

def main():
    x,y,z = map(int,input().split())
    if x < y:
        ans = x
        y -= x
        x = 0
        if z > y:
            z -= y
            ans += y + z//2
            y = 0
        else:
            ans += z
    else:
        ans = y
        x -= y
        y = 0
        if z > x:
            z -= x
            ans += x + z//2
            x = 0
        else:
            ans += z
    
    print(ans)  
    
if __name__ =='__main__':
    main()