Summation of series

/*
* Author Name: M.A. Yousuf Sir
* Call: +880 191 55 84 839 (8.00 am to 10.00 pm GMT+6 )
* Summation Of Series: 1+3+5+.......+30
*/
#include<stdio.h>
#include<conio.h>
main(){
 int a,s;
a=1;
s=0;
while(a<=30){
s = s+a;
a+=2;
}
printf("sum=%d",s);
}