#include <iostream>
using namespace std;
int main()
{
    setlocale(LC_CTYPE, "Russian");
    double x, a = 8, b = 12, S, h, S1, S2, L1, L2;
    int i, n=200;
    h = (b - a) / (2 * n);
    x = a + 2 * h;
    S1 = 0;
    S2 = 0;
    for (i = 1; i < n; i++)
    {
        S2 += 2 - pow(x, 2) + x;
        x += h;
        S1 += 2 - pow(x, 2) + x;
        x += h;
    }
    L1 = 2 - pow(a, 2) + a;
    L2 = 2 - pow(b, 2) + b;
    S = h*(L1 + 4 * (L1 + h) + 4 * S1 + 2 * S2 + L2) / 3;
    cout << "S = " << S << "\n";
    system("pause");
    return 0;
}