***#include<bits/stdc++.h> using namespace std;</p>

int main(){ long long n,sum=0; string a; cin>>n; for(long long i=0;i<n;i++){ cin>>a; stack stk; if(a.size()%2==1){ continue; } for(long long j=0;j<(long long)a.size();j++){ if(!(stk.empty())&&stk.top()==a[j]){ stk.pop(); }else{ stk.push(a[j]); } } if(stk.empty()){ sum++; } } cout<<sum; return 0; }***</u></u>