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/*
3
biteabbsirontailboltbite
bite tail bolt

 _____ _             _              _           _
|_   _| |__   ___   / \   _ __  ___| |__  _   _| |
  | | | '_ \ / _ \ / _ \ | '_ \/ __| '_ \| | | | |
  | | | | | |  __// ___ \| | | \__ \ | | | |_| | |
  |_| |_| |_|\___/_/   \_\_| |_|___/_| |_|\__,_|_|

*/
#include<bits/stdc++.h>
using namespace std;
#define N  100005

int dp[N];
int n,m;
string s;
vector<string>v(N);

int fun(int i)
{
	if(i<=-1)
		return 0;
	if(dp[i]!=-1)
		return dp[i];
	int ans=0;
	for(int j=0;j<m;j++)
	{
		if(i-v[j].length()+1<0)
			continue;
		if(s.substr(i-v[j].length()+1,v[j].length())==v[j])
			ans=max(fun(i-v[j].length())+(int)v[j].length(),ans);
	}
	dp[i]=ans;
	return ans;
}

void solve()
{
	cin>>m;
	cin>>s;
	n=s.length();
	for(int i=0;i<=n;i++)
		dp[i]=-1;
	for(int i=0;i<m;i++)
		cin>>v[i];
	cout<<n-fun(n-1);
	return;
}
int main()
{
	int TESTS=1;
//	cin>>TESTS;
	while(TESTS--)
	{
		solve();
	}
	return 0;
}