Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
	"strings"
)

func main() {
	fmt.Println(resolve(parseProblem(os.Stdin)))
}

func parseProblem(r io.Reader) int {
	const (
		initialBufSize = 100000
		maxBufSize     = 1000000
	)
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	p, q := scanInt(sc), scanInt(sc)
	base := 1
	d := newRational(p, q).denomi
	for k := range primeFactories(d) {
		base *= k
	}
	return base
}

func isPrime(n int) bool {
	for i := 2; i*i <= n; i++ {
		if n%i == 0 {
			return false
		}
	}
	return true
}

func eratosthenes(n int) []bool {
	t := make([]bool, n)
	for i := 2; i < len(t); i++ {
		t[i] = true
	}
	for i := 2; i < len(t); i++ {
		if !t[i] {
			continue
		}
		for j := 2; j*i < len(t); j++ {
			t[j*i] = false
		}
	}
	return t
}

func primes(n int) chan int {
	ch := make(chan int)
	go func() {
		t := eratosthenes(n)
		for i := 2; i < len(t); i++ {
			if !t[i] {
				continue
			}
			ch <- i
		}
		close(ch)
	}()
	return ch
}

func primeFactories(n int) (terms map[int]int) {
	terms = map[int]int{}
	num := n
	for f := 2; f*f <= n; f++ {
		if num%f != 0 {
			continue
		}
		ex := 0
		for num%f == 0 {
			num /= f
			ex++
		}
		terms[f] = ex
	}
	if num > 1 {
		terms[num] = 1
	}
	return
}

type rational struct {
	frac, denomi int
	neg          int
}

func newRational(frac, denomi int) rational {
	r := rational{frac: frac, denomi: denomi}
	r.canonicalize()
	return r
}

func ratMul(x, y rational) rational {
	r := rational{
		frac:   x.frac * y.frac,
		denomi: x.denomi * y.denomi,
	}
	r.canonicalize()
	return r
}

func ratDiv(x, y rational) rational {
	return ratMul(x, ratInv(y))
}

func ratInv(x rational) rational {
	return rational{frac: x.denomi, denomi: x.frac}
}

func ratAdd(x, y rational) rational {
	r := rational{
		frac:   x.frac*y.denomi + y.frac*x.denomi,
		denomi: x.denomi * y.denomi,
	}
	r.canonicalize()
	return r
}

func ratSub(x, y rational) rational {
	return ratAdd(x, rational{frac: -y.frac, denomi: y.denomi})
}

func (r rational) Float64() float64 {
	b := float64(r.frac) / float64(r.denomi)
	if r.neg == 1 {
		return -b
	}
	return b
}

func (r rational) String() string {
	b := fmt.Sprintf("%d/%d", r.frac, r.denomi)
	if r.neg == 1 {
		return "-" + b
	}
	return b
}

func (r rational) equal(other rational) bool {
	r.canonicalize()
	other.canonicalize()

	return r.neg == other.neg &&
		r.frac == other.frac &&
		r.denomi == other.denomi
}

func (r *rational) canonicalize() {
	if r.frac < 0 {
		r.neg ^= 1
		r.frac = -r.frac
	}
	if r.denomi < 0 {
		r.neg ^= 1
		r.denomi = -r.denomi
	}
	d := gcd(r.frac, r.denomi)
	r.frac /= d
	r.denomi /= d
}

func nextRational(sc *bufio.Scanner) rational {
	s := nextString(sc)
	i := strings.Index(s, ".")
	if i != -1 {
		decimalDigit := len(s) - i - 1
		fr, _ := strconv.Atoi(strings.Replace(s, ".", "", 1))
		return newRational(fr, int(math.Pow10(decimalDigit)))
	}
	i = strings.Index(s, "/")
	if i != -1 {
		fr, _ := strconv.Atoi(s[0:i])
		de, _ := strconv.Atoi(s[i+1 : len(s)])
		return newRational(fr, de)
	}
	fr, _ := strconv.Atoi(s)
	return newRational(fr, 1)
}
func gcd(a, b int) int {
	for b > 0 {
		t := a / b
		a, b = b, a-t*b
	}
	return a
}
func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	a, _ := strconv.Atoi(sc.Text())
	return int(a)
}

func nextString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func resolve(n int) int {
	return n
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: #include <bits/stdc++.h>
 
using namespace std;
 
#define INF 1001000100010001000
#define MOD 1000000007
#define EPS 1e-10
#define int long long
#define rep(i, N) for (int i = 0; i < N; i++)
#define Rep(i, N) for (int i = 1; i < N; i++)
#define For(i, a, b) for (int i = (a); i < (b); i++)
#define pb push_back
#define mp make_pair
#define i_i pair<int, int>
#define vi vector<int>
#define vvi vector<vi >
#define vb vector<bool>
#define vvb vector<vb >
#define vp vector< i_i >
#define all(a) (a).begin(), (a).end()
#define Int(x) int x; scanf("%lld", &x);
 
//int dxy[5] = {0, 1, 0, -1, 0};
// assign
 
int gcd(int a, int b);


signed main()
{
    Int(p);
    Int(q);

    while (p && q) {
        int base = gcd(p, q);
        q /= base;
        int ans = 1;
        for (int i = 2; i <= q; i++) {
            if (!(q % i)) {
                ans *= i;
                while (!(q % i)) {
                    q /= i;
                }
            }
        }
        cout << ans << endl;
        cin >> p >> q;
    }

    return 0;
}

int gcd(int a, int b)
{
    if (!b) {
        return a;
    } else {
        gcd(b, a%b);
    }
}

C++: #include "bits/stdc++.h"

#define REP(i,n) for(ll i=0;i<n;++i)
#define RREP(i,n) for(ll i=n-1;i>=0;--i)
#define FOR(i,m,n) for(ll i=m;i<n;++i)
#define RFOR(i,m,n) for(ll i=n-1;i>=m;--i)
#define ALL(v) (v).begin(),(v).end()
#define PB(a) push_back(a)
#define UNIQUE(v) v.erase(unique(ALL(v)),v.end());
#define DUMP(v) REP(aa, (v).size()) { cout << v[a]; if (a != v.size() - 1)cout << " "; else cout << endl; }
#define INF 1000000001ll
#define MOD 1000000007ll
#define EPS 1e-9

const int dx[8] = { 1,1,0,-1,-1,-1,0,1 };
const int dy[8] = { 0,1,1,1,0,-1,-1,-1 };


using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
ll max(ll a, int b) { return max(a, ll(b)); }
ll max(int a, ll b) { return max(ll(a), b); }
ll min(ll a, int b) { return min(a, ll(b)); }
ll min(int a, ll b) { return min(ll(a), b); }
///(?´????????`)(?´????????`)(?´????????`)(?´????????`)(?´????????`)(?´????????`)///
int gcd(int a, int b) {
	if (!b)return a;
	return gcd(b, a%b);
}
int fact(int n) {
	int res = 1, i = 2;
	int p = n;
	while (i*i<=p) {
		if (n % i == 0) {
			res *= i;
			res *= fact(n / i);
			break;
		}
		++i;
	}
	if (res == 1)return n;
	else return res;
}
int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int p, q;
	cin >> p >> q;
	int c = gcd(p, q);
	p /= c; q /= c;
	int i = 2;
	cout << fact(q) << endl;
	return 0;
}

C++: #include <stdio.h>
#include <math.h>

int gcd(int a, int b) {
  int t;
  while(b) {
    t = a % b;
    a = b;
    b = t;
  }
  return a;
}

int main(void){
  int p, q, i, j, ans = 1, bef = 0;
  scanf("%d%d", &p, &q);
  q /= gcd(p, q);
  for(i = 2; i <= sqrt(q) + 1;) {
    if(!(q % i)) {
      if(bef != i) ans *= i, bef = i;
      q /= i;
    } else ++i;
  }
  if(bef != q) ans *= q;
  printf("%d\n", ans);
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

int main(){
  int p,q,t,ans=1,num;
  set<int> s;
  cin>>p>>q;
  num=t=q/__gcd(p,q);
  for(int i=2;i*i<=num;i++){
    if(!(num%i)){
      s.insert(i);
      while(!(num%i))num/=i;
    }
  }
  set<int>::iterator ite=s.begin();
  while(ite!=s.end())ans*=*ite,ite++;
  if(ans==1)ans=t;
  cout<<ans<<endl;
  return 0;
}