#include
using namespace std;
int main()
{
double rate = 5;
double initial_balance = 10000;
double balance = initial_balance;
int year = 0;
while (balance < 2 * initial_balance){
balance = balance * (1 + rate / 100);
year++;
}
cout << "The investment doubled after " << year << " years.\n";
return 0;
}