#include <bits/stdc++.h> using namespace std; using ll = long long; const int INF = (int)1e9 + 1001010; const ll llINF = (long long)4e18 + 22000020; const string endn = "\n"; template <class T> inline auto vector2(size_t i, size_t j, const T &init = T()) { return vector(i, vector<T>(j, init)); } const string ELM_SEP = " ", VEC_SEP = endn; template <class T> istream &operator>>(istream &i, vector<T> &A) { for(auto &I : A) { i >> I; } return i; } template <class T> ostream &operator<<(ostream &o, const vector<T> &A) { int i = A.size(); for(const auto &I : A) { o << I << (--i ? ELM_SEP : ""); } return o; } template <class T> ostream &operator<<(ostream &o, const vector<vector<T>> &A) { int i = A.size(); for(const auto &I : A) { o << I << (--i ? VEC_SEP : ""); } return o; } template <class T> vector<T> &operator++(vector<T> &A, int) { for(auto &I : A) { I++; } return A; } template <class T> vector<T> &operator--(vector<T> &A, int) { for(auto &I : A) { I--; } return A; } template <class T, class U> bool chmax(T &a, const U &b) { return ((a < b) ? (a = b, true) : false); } template <class T, class U> bool chmin(T &a, const U &b) { return ((a > b) ? (a = b, true) : false); } ll floor(ll a, ll b) { if(b < 0) a = -a, b = -b; return (a >= 0) ? a / b : (a + 1) / b - 1; } ll ceil(ll a, ll b) { if(b < 0) a = -a, b = -b; return (a > 0) ? (a - 1) / b + 1 : a / b; } ll bit(unsigned long long val, unsigned long long digit) { return (val >> digit) & 1; } #ifdef DEBUG #include <cpp-dump/dump.hpp> #define dump(...) cpp_dump(__VA_ARGS__) namespace cp = cpp_dump; struct InitCppDump { InitCppDump() { if(!isatty(fileno(stderr))) CPP_DUMP_SET_OPTION(es_style, cpp_dump::es_style_t::no_es); CPP_DUMP_SET_OPTION(log_label_func, cp::log_label::line()); CPP_DUMP_SET_OPTION(max_iteration_count, 30); } } init_cpp_dump; #else #define dump(...) #endif // ==================== ここまでテンプレ ==================== int main(int argc, char *argv[]){ ios::sync_with_stdio(false); cin.tie(nullptr); ll x; cin >> x; if(x == 1){ cout << 2 << endl; cout << 1 << " " << 2 << endl; cout << "b g" << endl; return 0; } vector<ll> pfs; const ll MAX = (ll)2e5; { vector<ll> cand; for(int i = 3; i <= MAX; i++) cand.push_back(i); cand.push_back(2); for(auto i : cand){ if(x % i == 0){ pfs.push_back(i); while(x % i == 0) x /= i; } } } if(x > 1){ cout << -1 << endl; return 0; } dump(pfs); vector<pair<ll, ll>> edges; vector<char> color; ll last_brown; for(int i = 0; i < pfs.size(); i++){ ll pf = pfs[i]; if(i > 0) edges.emplace_back(last_brown, color.size()); last_brown = color.size(); color.push_back('b'); for(int j = 0; j < pf; j++){ edges.emplace_back(last_brown, color.size()); color.push_back('g'); } } if(color.size() > MAX){ cout << -1 << endl; return 0; } cout << color.size() << endl; for(auto [u, v] : edges){ cout << u+1 << " " << v+1 << endl; } cout << color << endl; return 0; }