function isPrime(n){

  if (n <= 1){

    return False;

  }

  if (n <= 3){

    return true;

  }

  if (n % 2 == 0 || n % 3 == 0){

    return false;

  }

  var i = 5;

  while(i * i <= n){

    if (n % i == 0 || n % (i + 2) == 0){

      return false;

    }

    i = i + 6;

  }

  return true;

}


function isStartingWith(number, startWith){

  return (number.toString())[0] == startWith.toString();

}


function generateLowestNumberWithDigit(digit){

  return 10 ** (digit - 1);

}


function generateBiggestNumberWithDigit(digit){

  return (10 ** digit) - 1;

}


function primeGenerator(digit, startWith){

  for(number = generateLowestNumberWithDigit(digit); number <= generateBiggestNumberWithDigit(digit); number = number + 1){

    if(isPrime(number) && isStartingWith(number, startWith)){

      console.log(number);

    }

  }

}

primeGenerator(3,5);