#include <iostream>
#include <cstring>
using namespace std;

int main() {
    int n;
    string cur, temp, subs;
    long long sum = 0;
    cin>>n;
    cin>>cur;
    for (int i = 1; i < n; ++i) {
        cin>>temp;
        if (temp.size() < cur.size() || (temp.size() == cur.size() && temp <= cur)) {
            subs = cur.substr(0, temp.size());
            if (temp < subs) {
                for (int j = 0; j < temp.size(); ++j) {
                    cur[j] = temp[j];
                }
                for (int j = temp.size(); j < min(cur.size(), temp.size() + 6); ++j) {
                    cur[j] = '0';
                }
                for (int j = cur.size(); j >= max(temp.size(), cur.size() - 6); --j) {
                    cur[j] = '0';
                }
                cur += '0';
            }
            else if (temp > subs) {
                for (int j = 0; j < temp.size(); ++j) {
                    cur[j] = temp[j];
                }
                for (int j = cur.size(); j >= max(temp.size(), cur.size() - 6); --j) {
                    cur[j] = '0';
                }
                for (int j = temp.size(); j < min(cur.size(), temp.size() + 6); ++j) {
                    cur[j] = '0';
                }
            }
            else {
                if (cur.size() == temp.size()) {
                    cur += '0';
                }
                else {
                    int q = cur.size() - 1;
                    while (q >= temp.size() && cur[q] == '9') --q;
                    if (q == temp.size() - 1) { // ?
                        for (int j = temp.size(); j < min(cur.size(), temp.size() + 6); ++j) cur[j] = 0;
                        cur += '0';
                    }
                    else {
                        cur[q]++;
                        for (int j = q + 1; j < cur.size(); ++j) {
                            cur[j] = '0';
                        }
                    }
                }
            }
        }
        else {
            cur = temp;
        }
        //cout<<cur<<' '<<temp<<' '<<cur.size() - temp.size()<<endl;
        sum += cur.size() - temp.size();
    }
    cout<<sum<<endl;
    return 0;
}