#include <stdio.h>
#include <math.h>

double f(double x, double y) { return x + y; }

int main() {
  double x = 0, y = 1;
  double h = 0.1;
  int n = 10;
  for (int i = 0; i < n; i++) {
    double k1 = h * f(x, y);
    double k2 = h * f(x + h / 2, y + k1 / 2);
    double k3 = h * f(x + h / 2, y + k2 / 2);
    double k4 = h * f(x + h, y + k3);
    y = y + (k1 + 2 * k2 + 2 * k3 + k4) / 6;
    x = x + h;
    printf("x = %.2f  y = %.6f\n", x, y);
  }
  return 0;
}