#include <iostream>
#include <cmath>

using namespace std;

/** 
   Accumulates interest in the local variable balance
   @param p the interest rate in percent
   @param n the number of periods the investment is held
*/
double future_value(double initial_balance, double p, int n)
{  
   double r = initial_balance * pow(1 + p / 100, n);
   return r;
}

int main()
{  
   cout << "Please enter the interest rate in percent:";
   double r;
   cin >> r;

   double balance = future_value(10000, r, 10);
   cout << "After ten years, the balance is "
      << balance << "\n";
   return 0;
}