text: #include <stdio.h>
  
  int main()
  {
    float fahr, celsius;
    int lower, upper, step;
  
    lower = 0;
    upper = 300;
    step = 20;
  
    printf("  F to C\n");
    printf("----------\n");
  
    fahr = upper;
    while (fahr >= lower) {
      celsius = (5.0/9.0) * (fahr-32.0);
      printf("%3.0f %6.1f\n", fahr, celsius);
      fahr = fahr - step;
    }
  
    printf("\n\n  C to F\n");
    printf("----------\n");
  
    float cel;
    cel = lower;
    while (cel <= upper) {
      fahr = (9.0 / 5.0) * cel + 32.0;
      printf("%3.0f %6.1f\n", cel, fahr);
      cel = cel + step;
    }  
  }
  