#include <bits/stdc++.h>
using namespace std;
#define task "main"
#define no "NO"
#define yes "YES"
#define F first
#define S second
#define vec vector
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
template<class X, class Y>
bool minimize(X &x, Y y) {
if (x > y) {
x = y;
return true;
}
return false;
}
const int MAX_N = 20;
int n;
string s[MAX_N];
int cnt[28][MAX_N];
int dp[1 << 16];
void solve() {
cin >> n;
FOR(i, 1, n) cin >> s[i];
memset(cnt, 0, sizeof(cnt));
FOR(i, 1, n) {
s[i] = " " + s[i];
int m = (int)s[i].size() - 1;
FOR(j, 1, m) cnt[s[i][j] - 'a'][i]++;
}
memset(dp, 0x3f, sizeof(dp));
FOR(i, 1, n) {
dp[1 << (i - 1)] = 0;
FOR(c, 0, 25) dp[1 << (i - 1)] += cnt[c][i];
}
FOR(mask, 1, (1 << n) - 1) {
if (__builtin_popcount(mask) == 1) continue;
int maxPrefix = 0;
FOR(c, 0, 25) {
int minn = INT_MAX;
FOR(i, 0, n - 1) if (mask >> i & 1) minimize(minn, cnt[c][i + 1]);
maxPrefix += minn;
}
for (int subMask = mask; subMask; subMask = (subMask - 1) & mask)
minimize(dp[mask], dp[subMask] + dp[mask ^ subMask] - maxPrefix);
}
cout << dp[(1 << n) - 1] + 1;
}
int32_t main() {
if (fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
bool multitest = 0;
int numTest = 1;
if (multitest) cin >> numTest;
while (numTest--) {
solve();
}
return 0;
}
/* Lak lu theo dieu nhac!!!! */
