#include <cstdio>
#include <cstring>
#include <cstdint>
#include <cstdlib>
#include <cstddef>
#include <cinttypes>

#include <type_traits>
#include <limits>
#include <vector>
#include <algorithm>

/* FastIO by rsk0315 (last update: 2018/02/21 00:36) */

namespace FastIn {
  static constexpr size_t BUF_SIZE=1<<17, INT_LEN=24, FLT_LEN=400;
  static char buf[BUF_SIZE|1]={}, *pos=buf, *endbuf=nullptr;
  FILE *fin;

  inline bool rebuffer() {
    // returns true <=> there is at least one unread character
    size_t rest=endbuf-pos;
    if (buf+rest > pos) {
      // buf[:pos] and buf[-pos:] are overlapping, which std::memcpy()
      // causes undefined behavior.
      return true;
    }

    std::memcpy(buf, pos, rest); 
    pos = buf;
    size_t len=std::fread(pos+rest, 1, BUF_SIZE-rest, fin);
    *(endbuf = buf + (rest+len)) = 0;

    return *pos;
  }

  inline bool scan(char &in) {
    if ((in = *pos)) {
      ++pos;
      return true;
    }

    return rebuffer() && (in = *pos++);
  }

  inline bool scan(char *in) {
    if ((*in = *pos) == 0) {
      if (rebuffer() && (*in = *pos) == 0) {
        return false;
      }
    }
    ++in;
    while (true) {
      if ((*in = *pos++) == 0) {
        if (rebuffer() && (*in = *pos++) == 0) {
          return true;
        }
      }
      ++in;
    }
  }

  inline bool scan(double &in) {
    if (pos + FLT_LEN >= endbuf && !rebuffer()) {
      in = 0.0;
      return false;
    }

    char *tmp;
    in = std::strtod(pos, &tmp);
    pos = tmp;
    return true;
  }

  template <class Int>
  inline bool scan(Int &in) {
    in = 0;

    // assume that no redundant whitespace appears
    if (pos + INT_LEN >= endbuf && !rebuffer()) {
      return false;
    }

    if (std::is_signed<Int>::value) {
      if (*pos == '-') {
        in = ~*++pos+'1';
        while (*++pos >= '0') {
          in = in*10 + ~*pos+'1';
        }
        ++pos;
        return true;
      }
    }

    // assume that numbers are separated by the character whose value is
    // less than '0' (e.g. whitespaces, newlines)
    do {
      in = in*10 + *pos-'0';
    } while (*++pos >= '0');
    ++pos;
    return true;
  }

  inline bool eat() {
    if (*pos > ' ') {
      return true;
    }

    do {
      if (*pos == 0 && !rebuffer()) {
        return false;
      }
    } while (*++pos <= ' ');

    return true;
  }

  inline bool eat(char ch) {
    if (*pos == ch) {
      return true;
    }

    do {
      if (*pos == 0 && !rebuffer()) {
        return false;
      }
    } while (*++pos != ch);

    return true;
  }

  class Scanner {
    bool rebuffer() {
      return FastIn::rebuffer();
    }

  public:
    Scanner(FILE *fin=stdin) {
      FastIn::fin = fin;
      endbuf = pos + std::fread(buf, 1, BUF_SIZE, fin);
    }

    template <class T>
    inline bool scan(T &in) {
      return FastIn::scan(in);
    }

    template <class First, class... Rest>
    inline bool scan(First &in, Rest &...ins) {
      return scan(in) && scan(ins...);
    }
  };
}

FastIn::Scanner cin;

template <class RandomIt>
auto rsort(RandomIt first, RandomIt last)
  -> typename std::enable_if<std::is_integral<
    typename RandomIt::value_type>::value>::type
{
  using IntType = typename RandomIt::value_type;
  intmax_t cur_shift=0, max_exp=sizeof(IntType);
  std::vector<IntType> work(last-first);
  for (int i=0; i<max_exp; ++i) {
    size_t num[256]={};

    for (RandomIt it=first; it<last; ++it)
      ++num[((*it)>>cur_shift)&255];

    {
      size_t tmp=0;
      for (int j=0; j<256; ++j)
        std::swap(tmp, num[j]+=tmp);
    }

    for (RandomIt it=first; it<last; ++it)
      work[num[((*it)>>cur_shift)&255]++] = *it;

    {
      size_t j=0;
      for (RandomIt it=first; it<last; ++it)
        *it = work[j++];
    }

    cur_shift += 8;
  }

  if (!std::is_signed<IntType>::value) return;

  RandomIt mid=last;
  for (RandomIt it=last; --it>=first;)
    if (*it >= 0) {
      mid = ++it;
      break;
    }

  if (mid == last)
    return;

  std::copy(first, mid, work.begin()+(last-mid));
  std::copy(mid, last, work.begin());
  std::copy(work.begin(), work.end(), first);
}

int main() {
  size_t N, M;
  cin.scan(N, M);

  std::vector<std::vector<uintmax_t>> B(N+1);
  for (size_t i=0; i<M; ++i) {
    uintmax_t p, y;
    cin.scan(p, y);
    B[p].emplace_back(y<<17|i);
  }

  for (size_t j=1; j<=N; ++j)
    std::sort(B[j].begin(), B[j].end());

  std::vector<std::pair<unsigned, size_t>> res(M);
  for (size_t j=1; j<=N; ++j)
    for (size_t k=0; k<B[j].size(); ++k)
      res[B[j][k]&0x1FFFFuLL] = {j, k+1};

  for (size_t i=0; i<M; ++i)
    printf("%06u%06zu\n", res[i].first, res[i].second);
}


Measured memory_bytes: 8704