1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
#include <bits/stdc++.h> // Tomasz Nowak
using namespace std;     // XIII LO Szczecin

#define FOR(i,a,n) for (auto i = (a), i##__ = (n); i <= i##__; ++i)
#define REP(i,n) FOR(i,0,(n)-1)
#define FORD(i,a,n) for (auto i = (a), i##__ = (n); i >= i##__; --i)
#define REPD(i,n) FORD(i,(n)-1,0)
#define ALL(x) x.begin(), x.end()
#define SZ(x) ((int) x.size())
#define X first
#define Y second
#define V vector
#define A array
constexpr char nl = '\n';

template<class A, class B> A&& mini(A &&a, B &&b) { if (b < a) a = b; return a; }
template<class A, class B> A&& maxi(A &&a, B &&b) { if (b > a) a = b; return a; }
int first_bit(int x) { return x == 0 ? 0 : sizeof(x) * 8 - __builtin_clz(x); }
int ceil2(int x) { return x < 2 ? x : 1 << first_bit(x - 1); }
constexpr int inf = 0x3f3f3f3f; 
constexpr long long inf_l = 0x3f3f3f3f3f3f3f3f;

#define _eif(a...) typename enable_if<a, int>::type()
#define _func(func, a...) template<class T> auto func(T &&x) -> decltype(a)
#define _rref(a...) typename remove_reference<a>::type
#define _create_trait(name, a...) \
    _func(_##name, a, true_type{}); \
    false_type _##name(...); \
    template<class T> struct name : decltype(_##name(declval<T>())) {};
struct Debug;
_create_trait(is_debug_func, x(declval<add_lvalue_reference<Debug>::type>()));
_create_trait(is_func, x())
_create_trait(is_string, string(x))
_create_trait(is_ptr, *x, _eif(is_string<T>() == false));
_create_trait(is_container, x.begin(), _eif(is_string<T>() == false))

template<class Iter> struct Off { Iter _a, _b; };
_func(O, _eif(is_container<T>() == true), Off<decltype(x.begin())>()) { return { ALL(x) }; }
_func(O, _eif(is_container<T>() == false), x) { return x; }

#define _operator(a...) _func(operator<<, a, *this)
struct Debug {
    Debug() {  cerr << boolalpha << fixed << setprecision(0); }
    ~Debug() { cerr << nl; }
    Debug& operator()(int x = 1) { REP(_, x) *this << "  "; return *this; }
    _operator(cerr << x, _eif(is_func<T>() == false && is_ptr<T>() == false && is_integral<_rref(T)>() == true)) { 
        using L = long long;
        if(abs(int(x)) == inf || abs(L(x)) == inf_l)
            cerr << ((int(x) == inf || L(x) == inf_l) ? "+∞" : (int(x) == -inf || L(x) == -inf_l) ? "-∞" : "?");
        else
            cerr << x;
        return *this; 
    }
    _operator(cerr << x, _eif(is_func<T>() == false && is_ptr<T>() == false && is_integral<_rref(T)>() == false)) {
        cerr << x;
        return *this;
    }
    _operator(x.first) { 
        return *this << "(" << O(x.first) << ", " << O(x.second) << ")"; }
    _operator(_eif(is_container<T>() == true)) {
        *this << "{\n";
        for (auto a = x.begin(); a != x.end(); ++a)
            *this << "  " << distance(x.begin(), a) << ": " << O(*a) << '\n';
        return *this << "}";
    }
    _operator(x._a) {
        *this << "{";
        for (auto a = x._a, b = x._b; a != b; ++a)
            *this << O(*a) << (next(a) == b ? "" : ", ");
        return *this << "}";
    }
    _operator(_eif(is_func<T>() == true)) { x(); return *this; }
    _operator(_eif(is_debug_func<T>() == true)) { x(*this); return *this; }
    _operator(_eif(is_ptr<T>() == true && is_func<T>() == false && is_debug_func<T>() == false)) {
        return *this << *x;
    }
};
struct DebugOff { 
    template<class T> DebugOff& operator<<(T&&) { return *this; }
    DebugOff& operator()(int = 0) { return *this; }
};

#ifdef DEBUG
# define D Debug()
#else
# define D DebugOff()
#endif
#define I(a...) #a ": " << a << "   "

using VI    = V<int>;
using VVI   = V<VI>;
using L     = long long;
using VL    = V<L>;
using VB    = V<bool>;
using II    = pair<int, int>;
using VII   = V<II>;
using VVII  = V<VII>;

// end of templates v8 by Tomasz Nowak

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	int n;
	cin >> n;
	vector<string> in(n);
	for(string &s : in)
		cin >> s;
	D << I(in);

	L answer = 0;
	string curr, prev = in.front();
	D << I(prev);

	FOR(it, 1, n - 1) {
		curr = in[it];
		int szc = SZ(curr), szp = SZ(prev);
		if(szc > szp) {
			prev = curr;
			D << I(it) << I(prev);
			continue;
		}

		int diff_pos = 0;
		while(diff_pos != min(szc, szp) && curr[diff_pos] == prev[diff_pos])
			++diff_pos;

		if(diff_pos == szc) { // curr is a prefix of prev
			answer += szp - szc;
			bool all_nine = true;
			FOR(i, diff_pos, szp - 1)
				if(prev[i] != '9') {
					all_nine = false;
					break;
				}

			if(all_nine) {
				++answer;
				FOR(i, diff_pos, szp - 1)
					prev[i] = '0';
				prev += '0';
			} else {
				++prev.back();
				REPD(i, szp)
					if(prev[i] > '9') {
						prev[i] = '0';
						++prev[i - 1];
					} else
						break;
			}
			D << I(it) << I(prev);
			continue;
		}

		// adding extra zeros to curr
		//
		int bonus = 0;
		if(prev[diff_pos] > curr[diff_pos])
			++bonus;

		if(szp > szc)
			answer += szp - szc;

		constexpr int mx_clear = 11;
		REP(i, min(mx_clear, szp))
			prev[i] = '0';
		FORD(i, szp - 1, max(n - mx_clear, 0))
			prev[i] = '0';
		while(SZ(prev) < szc)
			prev += '0';
		// totally cleared
		
		REP(i, szc)
			prev[i] = curr[i];
		// prev = curr;

		while(bonus --> 0) {
			++answer;
			prev += '0';
		}
		D << I(it) << I(prev);
	}

	cout << answer << nl;
}