Why this code of c has stop up-to 7 and how?

Question

#include<stdio.h>
void k(){
int a;
static int s=3;
a=++s;
printf("\n%d%d",a, s) ;
if(a<=5)
k();
printf("\n%d%d",a, s) ;
}
void main(){
k();
k();
}
output :44
55
66
66
56
46
77
77

Answer 1

what does abc() function do?

Answer 2

that's difficult to answer without seeing the rest of the code...