HDU1856-More is better

http://acm.hdu.edu.cn/showproblem.php?pid=1856

#include<stdio.h>
#define MAX 10000000
int fa[MAX],num[MAX];
int find(int x)
{
   return fa[x]==x?x:fa[x]=find(fa[x]);
}
void merge(int a,int b)
{
    int x,y;
    x=find(a);
    y=find(b);
    if(x!=y)
       fa[x]=y;
}
int count()
{
    int i,max=0;
    for(i=1;i<=MAX;i++)
       num[i]=0;
    for(i=1;i<=MAX;i++) 
        num[find(i)]++ ;
    for(i=1;i<=MAX;i++) 
       if(num[i]>max) 
          max=num[i] ;
    return max ;
}
int main(void)
{
    int n,a,b,i;
    while(scanf("%d",&n)!=EOF)
    {
        for(i=1;i<=MAX;i++)
           fa[i]=i;
        for(i=1;i<=n;i++)
        {
            scanf("%d%d",&a,&b);
            merge(a,b);
        }
        printf("%d\n",count());
    }
    return 0;
}