27.95

#include "stdafx.h"
#include <iostream>
#include <vector>
#include <conio.h>
using namespace std;

void debugPrint(short z);
void countCalc(vector<int> input);
void countCalc(vector<int> input1, vector<int> input2);

vector<int> critNumbers[4];
//0 = 1; 1 = 3; 2 = 7; 3 = 9;
short n = 0;
int mainCount = 0;

int main()
{
    cin >> n;
    for (int i = 0; i < n; i++) {
        int x = 0;
        cin >> x;
        x %= 10;
        switch (x)
        {
        case 1:
            critNumbers[0].push_back(i);
            break;
        case 3:
            critNumbers[1].push_back(i);
            break;
        case 7:
            critNumbers[2].push_back(i);
            break;
        case 9:
            critNumbers[3].push_back(i);
            break;
        }
    }
    countCalc(critNumbers[0]);
    countCalc(critNumbers[1], critNumbers[2]);
    countCalc(critNumbers[2], critNumbers[1]);
    countCalc(critNumbers[3]);
    cout << mainCount;
    _getch();
    return 0;
}

void countCalc(vector<int> input) {
    int lowBorder = 0;
    for (int i = 0; i < input.size(); i++) {
        if (lowBorder == 0) {
            lowBorder = i + 1;
        }
        int q = lowBorder;
        bool isntFound = true;
        while (q < input.size() && isntFound) {
            if (input[q] - input[i] - 1 >= 4) {
                mainCount += input.size() - q;
                lowBorder = q;
                isntFound = false;
            }
            q++;
        }
    }
}

void countCalc(vector<int> input1, vector<int> input2) {
    int lowBorder = 0;
    for (int i = 0; i < input1.size(); i++) {
        int q = lowBorder;
        bool isntFound = true;
        while (q < input2.size() && isntFound) {
            if (input2[q] - input1[i] - 1 >= 4) {
                mainCount += input2.size() - q;
                lowBorder = q;
                isntFound = false;
            }
            q++;
        }
    }
}