1764번: 듣보잡

#include<iostream>

#include<set>

#include<string>

using namespace std;

int main()

{

int n, m, count = 0;

cin >> n >> m;

set<string> listen, damn;

string name;

cin.ignore();

for (int i = 0; i < n; ++i)

{

getline(cin, name);

listen.insert(name);

}

for (int i = 0; i < m; ++i)

{

getline(cin, name);

if (listen.count(name))

{

damn.insert(name);

++count;

}

}

cout << count << endl;

for (set<string>::iterator iter = damn.begin(); iter != damn.end(); ++iter)

cout << *iter << endl;

}