WA on test #1 求助

#include<bits/stdc++.h>
using namespace std;
map<string,bool>pl;
int main()
{
    int n,m;cin>>n>>m;int cnt=0;
    string t;getline(cin,t);
    while(n--){string s;getline(cin,s);pl[s]=true;}
    while(m--){string s;getline(cin,s);cnt+=pl[s];}
    cout<<cnt;
}