#include<math.h>
#include<iostream>

using namespace std;

double
euler(double y, double f, double dt)
{
  double new_y = y + f*dt;
  return new_y;
}

int
main()
{
  double t, dt;
  double ts, t0, r;
  int nsteps;

  cout << "Input initial temperature (T0):" << endl;
  cin >> t0;
  cout << "Input temp. of environment (Ts):" << endl;
  cin >> ts;
  cout << "Input cooling rate (r):" << endl;
  cin >> r;
  cout << "Input step (dt):" << endl;
  cin >> dt;
//  cout << "Input number of steps:" << endl;
//  cin >> nsteps;
//  Alternatively:
  double tmax;
  cout << "Maximum time (tmax):" << endl;
  cin >> tmax;
  nsteps = tmax/dt;
  
  t = t0;
  for(int i = 1; i <= nsteps; i++){
    t = euler(t, -r*(t-ts), dt);
    cout << i*dt << " " << t << endl;
  }

  return 0;
}