```
#include<>stdio.h
main()
{
int n,s=0,i=1;
L1:printf("enter a range of numbers:");
scanf("%d",&n)
if(n<1){printf("\wrong input");
goto L1;}
while
{
s+=i;
i+=2;
}
printf("\nthe sum of the series is=%d,s");
getch();
}
```

the above program is meant to find out the sum S=1+3+5+7+....+N

can any on explain me,the significance of talking i+=2??