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

using ll = long long;

ll ipow10(int a) {
    assert(a>=0);
    ll r = 1;
    while (a--) r *= 10;
    return r;
}

ll ilog10(ll a) {
    assert(a>=0);
    ll r = 0;
    while (a>0) { r ++; a /= 10; }
    return r;
}

const int SPS = 9;

struct bnum {
    string start;
    int exp=0;
    long end=0;

    void check() {
        if (exp > 0) assert(start.size() == SPS);
        assert((start.size() > 0) ^ (exp == 0));
        if (exp > 0 && exp < 18) assert(ipow10(exp) > end);
    }

    void simplify() {
        check();
        if(end > (ll)1e16) {
            string s = to_string(end);
            start = s.substr(0, SPS);
            exp = s.size() - SPS;
            end = stoll(s.substr(SPS));
            check();
        }
    }

    string pr() {
        string s = to_string(end);
        if (exp > 0)
            while (s.size() != exp) s = ('0') + s;
        return start + s;
    }
};

bnum simple(ll a) {
    bnum b;
    b.start = "";
    b.exp = 0;
    b.end = a;
    return b;
}

pair<bnum, int> nextnum(bnum prev, ll prefix) {
    if (prev.exp == 0) {
        if (prefix > prev.end) return {simple(prefix), 0};

        int delta_count = ilog10(prev.end) - ilog10(prefix);
        ll pref0 = prefix * ipow10(delta_count);
        ll prefF = (prefix + 1) * ipow10(delta_count);

        ll cand = prev.end + 1;
        if (cand < pref0) return make_pair(simple(pref0), delta_count);
        if (cand < prefF) return make_pair(simple(cand), delta_count);
        return make_pair(simple(pref0 * 10), delta_count + 1);
    } else {
        string sprefix = to_string(prefix);
        string soprefix = sprefix;
        while (sprefix.size() < SPS) sprefix.push_back('0');
        int added_digits = SPS + prev.exp - ilog10(prefix);

        assert(sprefix.size() == prev.start.size());

        // cout  << prev.start.substr(0, soprefix.size()) << " " <<  soprefix << endl;
        if (prev.start.substr(0, soprefix.size()) == soprefix) {
            bnum n = prev;
            n.end ++;
            n.start = prev.start;
            return {n, added_digits};
        } else if (sprefix > prev.start) {
            bnum n = prev;
            n.end = 0;
            n.start = sprefix;
            return {n, added_digits};
        /*} else if (sprefix == prev.start) {
            bnum n = prev;
            n.end ++;
            n.start = sprefix;
            return {n, added_digits};*/
        } else {
            bnum n = prev;
            n.end = 0;
            n.start = sprefix;
            n.exp ++;
            return {n, added_digits + 1};
        }
    }
    abort();
}


int main() {
    ios_base::sync_with_stdio(0);
    int n;
    cin >> n;
    bnum curr; cin >> curr.end;
    ll res = 0;
    for (int i=1; i < n; i++) {
        ll newn;
        cin >> newn;
        curr.simplify();
        auto r = nextnum(curr, newn);

        curr = r.first;
        res += r.second;
        //cerr << "num " << newn << endl;
        //cerr << "curr: " << curr.start << " ..." << curr.exp <<  "... " << curr.end << endl;
        //cout << "curr: " << curr.pr() << endl;
    }
    cout << res << endl;
}