#include <iostream>

// The sigma_1(n) function returns the sum of the
// positive divisors of a positive integer 'n'.
//
// For example, the positive divisors of 12 are
//
//     1, 2, 3, 4, 6, 12,
//
// so
//
//     sigma_1(12) = 1 + 2 + 3 + 4 + 6 + 12 = 28.
//
// For a prime number 'p', the only positive divisors
// are 1 and p, and therefore
//
//     sigma_1(p) = 1 + p.
//
// Write a function that calculates the sum of the
// positive divisors of 'n'.
//
// If n <= 0, return 0.

// Function declarations
int main();
int sigma1( int n );

// Function definitions
int main() {
    for ( int m{ 0 }; m <= 50; ++m ) {
        std::cout << "sigma1(" << m << ") = "
                  << sigma1( m ) << std::endl;
    }

    return 0;
}

int sigma1( int n ) {
    return 0;
}



























// Hint:
// Iterate through all the integers 'k' from 1 through n.
// If n%k == 0, then 'k' is a divisor of 'n', so add 'k'
// to the sum.














































// Here is one solution:

/*
int sigma1( int n ) {
    if ( n <= 0 ) {
        return 0;
    }

    int sum{ 0 };

    for ( int k{ 1 }; k <= n; ++k ) {
        if ( n%k == 0 ) {
            sum += k;
        }
    }

    return sum;
}
*/