C Program to convert Celcius to Fahernheit

/*to convert celcius into fahernheit*/
#include <stdio.h>
#include<stdlib.h>
int main()
{
     int fahr, celsius;
     int lower, upper, step;
     lower = 0;    
     upper = 300;   
     step = 20;     
     fahr = lower;
     while (fahr <= upper)
    {
         celsius = 5 * (fahr-32) / 9;
         printf("%d\t%d\n", fahr, celsius);
         fahr= fahr + step;
    }
    system("pause");
    return 0;
}