function levenshtein(s,t) {
  if(s == t) return 0;
  if(s.length === 0) return t.length;
  if(t.length === 0) return s.length;

  var v0 = Array(t.length+1),
      v1 = Array(t.length+1);

  for(var i=0; i<v0.length; i++) v0[i]=i;
  for(i=0; i<s.length; i++) {
    v1[0]=i+1;
    for(var j=0; j<t.length; j++)
      v1[j+1] = Math.min(v1[j]+1, v0[j+1]+1, v0[j]+(s[i]==t[j]?0:1));
    for(j=0; j<v0.length; j++) v0[j]=v1[j];
  }
  return v1[t.length];
}

#include <stdio.h>
#include <stdbool.h>

bool is_prime(long double number) {
    ...
    else if (number == 1)
        return false;
    else if (number == 2)
        return true;
    ....
}

int main(int argc, char *argv[]) {
    bool primality;
    long double number;
    scanf("%Lf", &number);
    if(is_prime(number))
        printf("The number is prime.\n");
    else
        printf("The number isn't prime.\n");
    return 0;
}

throw `ball`; // :3

for(                              )_3=_(_3,_2);
      ;  _1>0  ;  _1=_(_1,_(~1,1))