#include <bits/stdc++.h>
#define int long long
using namespace std;

const int N = 1e5 + 10;
int n;
int dp[N];

signed main()
{
    cin >> n;
    int ans = 0;
    for(int i = 1; i <= n; i ++ )
    {
        string s;
        cin >> s;

        int a = s[0] - '0', b = s[s.size() - 1] - '0';
        dp[b] = max(dp[b], dp[a] + 1);
        ans = max(ans, dp[b]);
    }
    cout << n - ans;
}