Hack

#ifdef __GNUC__
#pragma GCC target("sse4,avx")
#endif
#include <immintrin.h>
#include <algorithm>
#include <string>
#include <iostream>
#include <vector>
#include <cstdint>
#include <numeric>
#include <fstream>
#include <sstream>

void run(std::ostream& out) {
  int mod = 256279;
  int n = 1000000000 / mod - 1;
  int mult = 200000 / n;
  if (mod * (n + 1) > 1000000000) {
    std::cerr << "overflow\n";
  }
  out << n * mult << std::endl;
  for (int j = 0; j < mult; j++) {
    for (int i = 0; i < n; i++) {
      out << i * mod + 2 * j + 1 << " " << i * mod + 2 * j + 2 << std::endl;
    }
  }
}

int main() {
  std::cin.sync_with_stdio(false);
  std::cin.tie(nullptr);
  run(std::cout);
  return 0;
}