i have this code and its output is 54. my question is, can someone please explain to me the process of getting this certain output, which is said to be 54. thank you. :)

```
#include<stdio.h>
#include<conio.h>
int sumS (int n, int m);
void main ()
{
int x=2, y=5;
clrscr();
printf("%d", sumS(x, y));
getch();
}
int sumS (int n, int m)
{
if (n==m)
return n*m;
else
return (n*n) + sumS (n+1, m)
}
```