#include <iostream>
#include <fstream>

using namespace std;

int main() {
    setlocale(LC_ALL, "ru");
    ifstream f;
    int arr[10];
    int sum = 0;
    f.open("C:\\sum.txt", ios::in);
    if (f.is_open()) {
        for (int i = 0; i <= 9; i++) {
            cout << "Введите " << i + 1 << " число:";
            cin >> arr[i];
        }
        for (int i = 0; i < 10; ++i) {
            sum += arr[i];
        }
    }
    ofstream fin;
    fin.open("C:\\sum.txt");
    fin << sum;
    fin.close();
}