const primorial=2*3*5*7*11*13*17*19*23*29;
var largest=0;
var sblistlength=0;

function hcfnaive(x, y) {
  x = Math.abs(x);
  y = Math.abs(y);
  while(y) {
    var t = y;
    y = x % y;
    x = t;
  }
  return x;
}

for(i=0; i<primorial; i++){
  var k=0
  while(hcfnaive(i+k,primorial)!=1 || hcfnaive(i-k,primorial)!=1){
    k=k+1
    if(k==213) sblistlength = sblistlength+1;
  }

  if(k>largest) largest=k;
}
console.log("length: " + sblistlength);
console.log("largest: " + largest);
console.log("primorial: " + primorial);