#include <bits/stdc++.h>
using namespace std;
template <typename T, typename U>
inline void smin(T &a, U b) {
  if (a > b) a = b;
}
template <typename T, typename U>
inline void smax(T &a, U b) {
  if (a < b) a = b;
}
template <typename T>
inline void gn(T &first) {
  char c, sg = 0;
  while (c = getchar(), (c > '9' || c < '0') && c != '-')
    ;
  for ((c == '-' ? sg = 1, c = getchar() : 0), first = 0; c >= '0' && c <= '9';
       c = getchar())
    first = (first << 1) + (first << 3) + c - '0';
  if (sg) first = -first;
}
template <class T, class T1>
inline void gn(T &first, T1 &second) {
  gn(first);
  gn(second);
}
template <class T, class T1, class T2>
inline void gn(T &first, T1 &second, T2 &z) {
  gn(first);
  gn(second);
  gn(z);
}
template <typename T>
inline void print(T first) {
  if (first < 0) {
    putchar('-');
    return print(-first);
  }
  if (first < 10) {
    putchar('0' + first);
    return;
  }
  print(first / 10);
  putchar(first % 10 + '0');
}
template <typename T>
inline void println(T first) {
  print(first), putchar('\n');
}
template <typename T>
inline void printsp(T first) {
  print(first), putchar(' ');
}
template <class T, class T1>
inline void print(T first, T1 second) {
  printsp(first), println(second);
}
template <class T, class T1, class T2>
inline void print(T first, T1 second, T2 z) {
  printsp(first), printsp(second), println(z);
}
int power(int a, int b, int m, int ans = 1) {
  for (; b; b >>= 1, a = 1LL * a * a % m)
    if (b & 1) ans = 1LL * ans * a % m;
  return ans;
}
long long cnt[1000000], step[1000000], delay[1000000];
int p[1000000], pk, mp[1000000];
int main() {
  for (int i = 2; i < 1000000; i++) {
    if (mp[i]) continue;
    mp[i] = i;
    p[pk++] = i;
    if (i >= 1000) continue;
    for (int j = i * i; j < 1000000; j += i)
      if (!mp[j]) mp[j] = i;
  }
  int n;
  gn(n);
  for (int i = 0; i < n; i++) {
    int p;
    long long a;
    gn(p, a);
    cnt[p] = a;
  }
  long long k;
  gn(k);
  for (int i = 0; i < pk; i++) step[p[i]] = k;
  for (int flag = 1; flag--;) {
    for (int i = 0; i < pk; i++) {
      int n = p[i];
      if (cnt[n]) {
        if (!step[n]) continue;
        flag = 1;
        long long t = min(cnt[n], step[n]);
        cnt[n] -= t;
        step[n] -= t;
        delay[n] += t - 1;
        for (n--; n > 1; n /= mp[n]) cnt[mp[n]] += t;
      } else if (delay[n])
        delay[n]--;
      else if (step[n])
        step[n]--;
    }
  }
  for (int i = n = 0; i < pk; i++)
    if (cnt[p[i]]) n++;
  println(n);
  for (int i = 0; i < pk; i++)
    if (cnt[p[i]]) print(p[i], cnt[p[i]]);
  return 0;
}
