CodeForces 606A Magic Spheres

/* ***********************************************
Author        :Zhou Zhentao
Email         :774388357@qq.com
Created Time  :2015/12/15 12:45:27
File Name     :main.cpp
************************************************ */

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
using namespace std;

int a,b,c;
int x,y,z;
int flagA,flagB,flagC;
int flag2;

int main()
{
    while(~scanf("%d%d%d",&a,&b,&c))
    {
        scanf("%d%d%d",&x,&y,&z);

        flagA=0,flagB=0,flagC=0,flag2=0;

        int num=0;

        if(a>=x) flagA=flagA+a-x;
        else flag2=flag2+x-a;

        if(b>=y) flagB=flagB+b-y;
        else flag2=flag2+y-b;

        if(c>=z) flagC=flagC+c-z;
        else flag2=flag2+z-c;

        num=num+flagA/2;
        num=num+flagB/2;
        num=num+flagC/2;

        if(num>=flag2) printf("Yes\n");
        else printf("No\n");
    }
    return 0;
}