#include <bits/stdc++.h>
using namespace std;
int main() {
cin.tie(0)->sync_with_stdio(0);
int N;
cin >> N;
vector<array<int, 26>> g(N);
for (auto i = 0; i < N; ++i) {
fill(g[i].begin(), g[i].end(), 0);
string s;
cin >> s;
for (auto c : s) {
++g[i][c - 'a'];
}
}
vector<int> dp(1 << N, -1);
constexpr auto inf = (int)1e9;
auto pre = [&](auto mask) {
array<int, 26> cnt;
fill(cnt.begin(), cnt.end(), inf);
for (auto i = 0; i < N; ++i) {
if (mask >> i & 1) {
for (auto j = 0; j < 26; ++j) {
cnt[j] = min(cnt[j], g[i][j]);
}
}
}
auto ret = 0;
for (auto x : cnt) {
if (x < inf) {
ret += x;
}
}
return ret;
};
auto f = [&](auto self, int mask) -> int {
assert(mask);
auto &ret = dp[mask];
if (~ret) return ret;
if (__builtin_popcount(mask) == 1) {
auto i = __builtin_ctz(mask);
ret = accumulate(g[i].begin(), g[i].end(), 0);
return ret;
}
ret = inf;
auto p = pre(mask);
for (auto i = (mask - 1) & mask; i > 0; i = (i - 1) & mask) {
ret = min(ret, self(self, i) + self(self, mask ^ i) - p);
}
return ret;
};
auto ans = f(f, (1 << N) - 1) + 1;
cout << ans;
}
