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//Piotr Golda
#include <iostream>
#include <vector>
#include <set>
#include <algorithm>

using ANumberT = std::vector < unsigned char > ;
using AContainerT = std::vector < ANumberT > ;

void rewriteNumber(ANumberT& aNumber, unsigned int a)
{
	if (a != 0)
	{
		rewriteNumber(aNumber, a / 10);
		aNumber.push_back(a % 10);
	}
}

AContainerT readInput()
{
	size_t N;
	AContainerT A;
	unsigned int a;
	std::cin >> N;
	A.resize(N);
	for (auto& aNumber : A)
	{
		std::cin >> a;
		rewriteNumber(aNumber, a);
	}
	return A;
}

void appendZeros(ANumberT& list, ANumberT::size_type count)
{
	list.insert(list.end(), count, ANumberT::value_type{ 0 });
}

enum class CMP
{
	EQUAL,
	GREATER,
	LOWER
};

void increment(ANumberT& lastNumber, const size_t lastNonChangableDigit, std::set<size_t>& nonZeros)
{
	size_t i{ 0 };
	for (i = lastNumber.size() - 1; i > lastNonChangableDigit; --i)
	{
		if (lastNumber[i] != 9)
		{
			++lastNumber[i];
			nonZeros.insert(i);
			return;
		}
		lastNumber[i] = 0;
	}
	lastNumber.push_back(0);
}

unsigned long long int compute( const AContainerT& A)
{
	unsigned long long int result{ 0 };
	ANumberT lastNumber{ A[0] };
	std::set<size_t> nonZeros;
	for (size_t i = 0; i < lastNumber.size(); ++i)
		if (lastNumber[i] != 0)
			nonZeros.insert(i);

	for (size_t i = 1; i < A.size(); ++i)
	{
		//std::cout << "comparing: " << lastNumber << " with " << A[i] << std::endl;
		if (lastNumber.size() < A[i].size())
		{
			lastNumber = A[i];
			nonZeros.clear();
			for (size_t i = 0; i < lastNumber.size(); ++i)
				if (lastNumber[i] != 0)
					nonZeros.insert(i);
			continue;
		}
		CMP cmp{ CMP::EQUAL };
		size_t idx{ 0 };
		for (idx = 0; idx < A[i].size(); ++idx)
		{
			if (cmp == CMP::EQUAL)
			{
				if (lastNumber[idx] < A[i][idx])
					cmp = CMP::LOWER;
				else if (lastNumber[idx] > A[i][idx])
					cmp = CMP::GREATER;
			}
			lastNumber[idx] = A[i][idx];
			if (lastNumber[idx] != 0)
				nonZeros.insert(idx);
		}
		if (cmp == CMP::EQUAL)
		{
			increment(lastNumber, A[i].size() - 1, nonZeros);
		}
		else
		{
			if (cmp == CMP::GREATER)
			{
				lastNumber.push_back(0);
			}
			auto it = nonZeros.rbegin();
			while (it != nonZeros.rend() && *it > A[i].size() - 1)
			{
				lastNumber[*it] = 0;
				nonZeros.erase(*it);
			}
		}
		result += (lastNumber.size() > A[i].size()) ? lastNumber.size() - A[i].size() : 0;
	}
	return result;
}

int main()
{
	std::ios_base::sync_with_stdio(false);
	auto A = readInput();
	std::cout << compute(A) << std::endl;

	return 0;
}