Timus-1496. Spammer

#include <bits/stdc++.h>

using namespace std;
#define pb push_back
#define FastIO ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define F first
#define S second
typedef long long ll;
typedef vector< int > vi;
typedef vector< ll > V;
typedef map<int, int > mp;
#define debug cout << -1 << endl;
#define REP(i, a, b) for(int i=a; i<b; i++)
#define pop pop_back
const ll MOD = 1000000007;
const int maxN = 2001;

int dx[] = {-1, 0, 1, -1, 1, -1, 0, 1};
int dy[] = {-1, -1, -1, 0, 0, 1, 1, 1};

void solve()
{
    int n;
    cin >> n;
    cin.ignore();
    map< string, int > m;
    while(n--) {
        string str;
        cin >> str;
        if(m[str]==1) cout << str << "\n";
        m[str]++;
    }
    return;
}

int main()
{
    FastIO;
    int t;
    t = 1;
    //cin >> t;
    while(t--){
        solve();
    }
    return 0;
}