#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main()
{
    ios::sync_with_stdio(false);
  cin.tie(0);
    ll i,j;
    ll t;
    vector <ll> a;
    cin>>t;
    while(t--)
    {
        char s[100005];
        cin>>s;
        ll open=0,close=0,flag1=0,flag=0,m=0;
        for(i=0;s[i]!='\0';i++)
        {
            open+=(s[i]=='(');
            close+=(s[i]==')');
            if(open<close)
                flag=1;
            m++;
        }
        ll open1=0,close1=0;
        for(i=m-1;i>=0;i--)
        {
            open1+=(s[i]=='(');
            close1+=(s[i]==')');
            if(open1>close1)
                flag1=1;
        }
        ll r=open-close;
        if(flag==1 and flag1==1)
            continue;
        //cout<<t<<" "<<r<<"\n";
        a.push_back(r);
    }
    if(a.size()>1)
    sort(a.begin(),a.end());
    i=0;
    j=a.size()-1;
    ll ans=0;
 
    while(i<j)
    {
        if(a[i]+a[j]==0)
        {
            ans++;
            i++;
            j--;
        }
        else if(a[i]+a[j]>0)
        {
            j--;
        }
        else
        {
            i++;
        }
    }
    cout<<ans;
}