WA on #8,10

code:

#include<bits/stdc++.h>
using namespace std;
map<string,int >mp;
int main(){
        string s1,s2;
        while(cin>>s1>>s2){
                mp[s1]++;
                mp[s2]++;
        }
        int cnt_ji=0;
        map<string,int>::iterator it;
        for(it=mp.begin();it!=mp.end();++it)
                if((it->second)&1)++cnt_ji;
        if(cnt_ji==0||cnt_ji==2)puts("Possible");
        else puts("Impossible");
}

验证码wmrn祭