#include<bits/stdc++.h>
#define maxn 17
#define INF 10000000
using namespace std;
int n;
string s[maxn];
int sl[maxn][26];
int dp[(1<<maxn) + 5];
vector<int>sz[maxn];
vector<int>tre;
int minn[26];
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
cin>>n;
for(int i=0;i<n;i++)
{
cin>>s[i];
for(auto x:s[i])
{
sl[i][x-'a']++;
}
}
for(int i=1;i<(1<<n);i++)
{
int br=0;
for(int j=1;j<=i;j*=2)
{
br+= (j & i)!=0;
}
sz[br].push_back(i);
}
for(int br=1;br<=n;br++)
{
for(auto subset:sz[br])
{
tre.clear();
for(int j=0;j<n;j++)
{
if((1<<j)&subset)tre.push_back(j);
}
if(br==1)
{
dp[subset]=s[tre[0]].size();
continue;
}
for(int j=0;j<26;j++)minn[j]=INF;
for(int j=0;j<br;j++)
{
for(int w=0;w<26;w++)
{
minn[w]=min(minn[w],sl[ tre[j] ][w]);
}
}
int presek=0;
for(int j=0;j<26;j++)presek+=minn[j];
/*if(subset==3)
{
cout<<presek<<endl;
}*/
dp[subset]=INF;
for(int j=1;j<(1<<br)-1;j++)
{
int subsub1=0;
int subsub2=0;
for(int w=0;w<br;w++)
{
if(j&(1<<w))subsub1+=1<<(tre[w]);
else subsub2+=1<<(tre[w]);
}
/*if(subset==3)
{
cout<<subsub1<<" "<<subsub2<<endl;
}*/
dp[subset]=min(dp[subset],dp[subsub1]+dp[subsub2]-presek);
}
}
}
//cout<<endl<<endl;
/*vector<int>v;
for(int i=1;i<(1<<n);i++)
{
v.clear();
for(int j=0;(1<<j)<=i;j++)
{
if(i&(1<<j))
{
v.push_back(j);
}
}
cout<<v.size()<<": ";
for(auto x:v)cout<<x<<" ";cout<<endl;
cout<<dp[i]<<endl<<endl;
}*/
cout<<dp[(1<<n)-1]+1<<endl;
return 0;
}
