#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<utility>
#include<map>
#include<set>
#include<queue>
#include<stack>
#include<functional>
#include<math.h>
#include<random>
#include <bitset>
using namespace std;
#define N (1000000000+7)
//#define N 998244353
#define INF 1e16
typedef long long ll;
typedef pair<int,int> P;
typedef pair<int,P> Q;
 
const int inf = (int)1e9; 
 
ll gcd(ll a, ll b) {
	if (b > a) {
		ll tmp = b;
		b = a;
		a = tmp;
	}
	if (a%b == 0)return b;
	else return gcd(b, a%b);
}


int main(void){
	int n;
	cin>>n;
	map<string,int>S;
	for(int i=0;i<n;i++){
		string s;
		cin>>s;
		S[s]++;
	}
	int ans1 = 0,ans2 = 0;
	for(auto [x,y]:S){
		if(y>ans1){
			ans1 = y;
			ans2 = x.size()-2;
		}
		if(y==ans1 && x.size()-2>ans2){
			ans2 = x.size()-2;
		}
	}
	cout<<ans2<<endl;
	return 0;

}