//Daniel Grzegorzewski
#include <bits/stdc++.h>
#pragma GCC optimize("O3")

#define MP make_pair
#define PB push_back
#define ST first
#define ND second
#define int long long

using namespace std;

typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef long long LL;

void init_ios() {
     ios_base::sync_with_stdio(0);
     cin.tie(0);
}

const int N = 2*(int)1e5 + 10;
const int LOL = 18;

int n, len, res;
string a[N];

bool check(const string& x) {
  if (x.size() >= LOL)
    len = x.size();
}

string dodaj(string co) {
  int nxt = 1;
  for (int i = (int)co.size()-1; nxt && i >= 0; --i) {
    if (co[i] == '9')
      co[i] = '0';
    else {
      co[i]++;
      nxt = 0;
    }
  }
  if (nxt)
    co = "1" + co;
  return co;
}

void modify(int i) {
  // a[i-1] krotszy od LOL
  if (len == 0) {
    if (a[i].size() > a[i-1].size())
      return;
    else if (a[i].size() == a[i-1].size()) {
      if (a[i] > a[i-1])
        return;
      ++res;
      a[i] += "0";
      check(a[i]);
      return;
    }
    else {
      string pref = a[i-1].substr(0, a[i].size());
      if (a[i] > pref) {
        while (a[i].size() < a[i-1].size()) {
          ++res;
          a[i] += "0";
        }
        check(a[i]);
      }
      else if (a[i] < pref) {
        while (a[i].size() <= a[i-1].size()) {
          ++res;
          a[i] += "0";
        }
        check(a[i]);
      }
      else {
        string suf = a[i-1].substr(a[i].size());
        string suf2 = dodaj(suf);
        if (suf.size() == suf2.size()) {
          res += suf.size();
          a[i] += suf2;
        }
        else {
          while (a[i].size() <= a[i-1].size()) {
            ++res;
            a[i] += "0";
          }
        }
        check(a[i]);
      }
    }
  }
  // a[i-1] co najmniej dlugosci LOL
  else {
    string pref = a[i-1].substr(0, a[i].size());
    if (pref > a[i]) {
      ++len;
      res += len-a[i].size();
      while (a[i].size() <= LOL)
        a[i] += "0";
    }
    else if (a[i] == pref) {
      res += len-a[i].size();
      while (a[i].size() <= LOL)
        a[i] += a[i-1][a[i].size()];
    }
    else {
      res += len-a[i].size();
      while (a[i].size() <= LOL)
        a[i] += "0";
    }
  }
}

signed main() {
  init_ios();
  cin >> n;
  for (int i = 1; i <= n; ++i)
    cin >> a[i];
  for (int i = 2; i <= n; ++i)
    modify(i);
  cout<<res<<"\n";
}