#include <bits/stdc++.h>
using namespace std;
namespace my_header {
const int INF = 0x3f3f3f3f;
inline char gchar() {
  char ret = getchar();
  for (; (ret == '\n' || ret == '\r' || ret == ' ') && ret != EOF;
       ret = getchar())
    ;
  return ret;
}
template <class T>
inline void fr(T &ret, char c = ' ', int flg = 1) {
  for (c = getchar(); (c < '0' || '9' < c) && c != '-'; c = getchar())
    ;
  if (c == '-') {
    flg = -1;
    c = getchar();
  }
  for (ret = 0; '0' <= c && c <= '9'; c = getchar()) ret = ret * 10 + c - '0';
  ret = ret * flg;
}
inline int fr() {
  int t;
  fr(t);
  return t;
}
template <class T>
inline void fr(T &a, T &b) {
  fr(a), fr(b);
}
template <class T>
inline void fr(T &a, T &b, T &c) {
  fr(a), fr(b), fr(c);
}
template <class T>
inline char wr(T a, int b = 10, bool p = 1) {
  return a < 0 ? putchar('-'), wr(-a, b, 0)
               : (a == 0 ? (p ? putchar('0') : p)
                         : (wr(a / b, b, 0), putchar('0' + a % b)));
}
template <class T>
inline T gcd(T a, T b) {
  return b == 0 ? a : gcd(b, a % b);
}
template <class T>
inline T fpw(T b, T i, T _m, T r = 1) {
  for (; i; i >>= 1, b = b * b % _m)
    if (i & 1) r = r * b % _m;
  return r;
}
};  // namespace my_header
using namespace my_header;
vector<string> pp;
vector<pair<int, int> > w;
vector<int> ans[1111111];
char str[1111111];
bool gw() {
  int t = 0;
  while ((str[t++] = gchar()) != ',')
    if (str[t - 1] == EOF) return false;
  str[t - 1] = 0;
  pp.push_back(string(str));
  w.push_back({(int)pp.size() - 1, fr()});
  return true;
}
int n, p, d;
void dfs(int l) {
  if (l > d) d = l;
  int x = w[p].second;
  ans[l].push_back(w[p].first);
  ++p;
  while (x--) dfs(l + 1);
}
int main() {
  while (gw())
    ;
  p = 0;
  n = (int)w.size();
  while (p < n) dfs(0);
  wr(d + 1), puts("");
  for (int i = 0; i < d + 1; ++i) {
    for (auto x : ans[i]) printf("%s ", pp[x].c_str());
    puts("");
  }
  return 0;
}
