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#include <cstdio>
#include <algorithm>
#include <cmath>

using namespace std;


struct result {
    int digits;
    unsigned long number;
};

const int MAX_NUMBERS = 200001;
const int MAX_DIGITS = 11;

int n;
unsigned long needed = 0;
unsigned long a[MAX_NUMBERS];
unsigned int actualDigits[MAX_DIGITS];
unsigned int lowerDigits[MAX_DIGITS];

inline bool endsWithAllNines(int lod) {
    bool answer = true;
    for (int i = 0; i <= lod; i++) {
        answer = answer && (lowerDigits[i] == 9);
    }
    return answer;
}

result fillNumber(unsigned long actual, unsigned long lower) {
    result res;
    res.digits = 0;
    res.number = actual;
    int actualDigitsCount = 0;
    int lowerDigitsCount = 0;    
    unsigned long number;
    if (actual > lower) {
        return res;
    } else if (actual == lower) {
        res.digits = 1;
        res.number = actual * 10;
        return res;
    }

    number = actual;
    while (number != 0) {
        actualDigits[actualDigitsCount] = number % 10;
        number /= 10;
        actualDigitsCount++;
    }
    number = lower;
    while (number != 0) {
        lowerDigits[lowerDigitsCount] = number % 10;
        number /= 10;
        lowerDigitsCount++;
    }
    int acd = actualDigitsCount - 1;
    int lod = lowerDigitsCount - 1;
    while (acd >= 0 && lod >= 0 && actualDigits[acd] == lowerDigits[lod]) {
        acd--;
        lod--;
    }
    if (acd >= 0 && lod >= 0) {
        if (actualDigits[acd] > lowerDigits[lod]) {
            res.digits = lowerDigitsCount - actualDigitsCount;
            for (int i = 0; i < res.digits; i++) {
                res.number *= 10;
            }
        } else {
            res.digits = lowerDigitsCount - actualDigitsCount + 1;
            for (int i = 0; i < res.digits; i++) {
                res.number *= 10;
            }
        }
    } else {
        if (endsWithAllNines(lod)) {
            res.digits = lod + 2;
            for (int i = 0; i < res.digits; i++) {
                res.number *= 10;
            }
        } else {
            res.digits = lod + 1;
            res.number = lower + 1;
        }
    }
    return res;
}

int main() {
    scanf("%d\n", &n);
    for (int i = 0; i < n; i++) {
		scanf("%lu\n", &a[i]);
	}
    for (int i = 1; i < n; i++) {
		if (a[i] <= a[i-1]) {
            result res = fillNumber(a[i], a[i-1]);
            needed += res.digits;
            a[i] = res.number;
        }
	}
    printf("%lu\n", needed);
    return 0;
}