static function in C language program

here is static local variable, not with the end of the function to undo, placed in the main function is meaningless, the following is the example of static :
void F ()
{
static int x=0;
int y=0;
x + +;
y++;
printf ("%d%d\n", x, y);
}
void Main ()
{
f ();
f ();
f ();


This runs 3 times f (), but static is only defined once and does not die with the end of the F () function , but y is a local variable, and 3 times it is created 3 times it has died 3 times, so its output is:
1 1
2 1
3 1

static function in C language program