I want to keep a variable's value to next call of run(), if I ran the code below for 2 bars period

Code:
function run(){
  //1. if(is(INITRUN)) int x=0;
  //2. if(is(FIRSTRUN)) int x=0;
  //3. int x=0;
  //4. static int x=0;
  
  printf("%i",x);
  x = 1;
  printf("%i",x);
}

#1, 2 and 3 got me 0101, implying x was set again at each bar run.
#4 got me 0111, which is what I want.

I thought if(is(INITRUN)) and if(is(FITSTRUN)) would only set variable x once.