// 14:47 - 15:23
#include <stdio.h>
#include <stdlib.h>
#define MAXSIZE 150

typedef struct node {
  char ch;
  int freq;
  struct node *l, *r;
} node;

typedef struct heap {
  int top;
  node **arr;
} heap;

node *newNode(char ch, int freq) {
  node *tr = malloc(sizeof(node));
  tr->l = tr->r = NULL;
  tr->ch = ch;
  tr->freq = freq;
  return tr;
}

heap *newHeap() {
  heap *h = malloc(sizeof(heap));
  h->top = 0;
  h->arr = malloc(sizeof(node *) * MAXSIZE);
  return h;
}

int parent(int i) { return (i - 1) / 2; }

int left(int i) { return i * 2 + 1; }

int right(int i) { return i * 2 + 2; }

void swap(node **l, node **r) {
  node *tmp = *l;
  *l = *r;
  *r = tmp;
}

void heapify(heap *h, int i) {
  // from up to down
  int smallest = i;
  int l = left(i), r = right(i);

  if (l < h->top && h->arr[smallest]->freq > h->arr[l]->freq) {
    smallest = l;
  }
  if (r < h->top && h->arr[smallest]->freq > h->arr[r]->freq) {
    smallest = r;
  }

  if (smallest != i) {
    swap(&h->arr[smallest], &h->arr[i]);
    heapify(h, smallest);
  }
}

void insert(heap *h, node *tr) {
  int i = h->top++;
  h->arr[i] = tr;

  while (h->arr[i]->freq < h->arr[parent(i)]->freq) {
    swap(&h->arr[i], &h->arr[parent(i)]);
    i = parent(i);
  }
}

node *extractMin(heap *h) {
  node *res = h->arr[0];
  h->arr[0] = h->arr[--h->top];

  heapify(h, 0);
  return res;
}

node *makeHuffmanTree(heap *h) {
  node *l, *r;
  node *tmp;
  while (h->top > 1) {
    l = extractMin(h);
    r = extractMin(h);

    tmp = newNode('#', l->freq + r->freq);
    tmp->l = l;
    tmp->r = r;

    insert(h, tmp);
  }
  return extractMin(h);
}

void printCode(node *tr, char *buf) {
  int i = 0;
  while (buf[i] == '0' || buf[i] == '1') {
    node *cur = tr;
    while (cur->ch == '#') {
      if (buf[i] == '0') {
        cur = cur->l;
      } else {
        cur = cur->r;
      }
      i++;
    }
    printf("%c", cur->ch);
  }
}

int main(void) {
  heap *h = newHeap();
  insert(h, newNode('a', 7));
  insert(h, newNode('b', 19));
  insert(h, newNode('c', 2));
  insert(h, newNode('d', 6));
  insert(h, newNode('e', 32));
  insert(h, newNode('f', 3));
  insert(h, newNode('g', 21));
  insert(h, newNode('h', 10));

  node *hTree = makeHuffmanTree(h);
  char buf[MAXSIZE];
  fgets(buf, MAXSIZE, stdin);

  printCode(hTree, buf);

  return 0;
}