[蓝桥杯2017初赛]兴趣小组

#include<iostream>
#include<string>
#include<algorithm>
#include<math.h>
#include<string.h>
#include<map>
#define ll long long
using namespace  std;
map<string,int>A;
map<string,int>B;
map<string,int>C;
int main()
{
    int ans=0,a=150,b=250,c=250;
    string s;
    while(a--)
    {
        cin>>s;
        A[s]=1;
    }
    while(b--)
    {
        cin>>s;
        B[s]=1;
    }
    while(c--)
    {
        cin>>s;
        C[s]=1;
    }
    ll n=max(A.size(),max(B.size(),C.size()));
    map<string,int>::iterator it;
    for(it=A.begin();it!=A.end();it++)
        if(B.count(it->first)&&C.count(it->first)==0)
            ans++;
    cout<<ans<<endl;
    //cout<<20<<endl;
    return 0;

}