#include <iostream>
#include <cmath>
using namespace std;

int main()
{
    const int numPaymentsPerYr = 12; //Prevent bugs, keep it simple.
    double loanSize, decIntPerYear, interestRate, totalPayments, decIntPerPayment, factor;
    int loanDuration;

    cout << "Please enter the size of the loan:";
    cin >> loanSize;

    cout << "Please enter the loan's duration:";
    cin >> loanDuration;

    totalPayments = numPaymentsPerYr * loanDuration;

    cout << "Please enter the interest rate:";
    cin >> interestRate;

    decIntPerYear = interestRate / 100;
    decIntPerPayment = interestRate / numPaymentsPerYr;

    factor = pow(1 - (decIntPerPayment),(-totalPayments)) / (decIntPerPayment);

    cout << loanSize / factor ;

    return 0;
}