#include "bits/stdc++.h" using namespace std; #pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #define INT(...) \ int __VA_ARGS__; \ IN(__VA_ARGS__) #define LL(...) \ ll __VA_ARGS__; \ IN(__VA_ARGS__) #define STR(...) \ string __VA_ARGS__; \ IN(__VA_ARGS__) #define CHR(...) \ char __VA_ARGS__; \ IN(__VA_ARGS__) #define DBL(...) \ double __VA_ARGS__; \ IN(__VA_ARGS__) #define ll long long #define cout std::cout #define yes cout<<"Yes"<<"\n" #define no cout<<"No"<<"\n" #define rep(i,a,b) for(int i=a;i=b;i--) #define fore(i,a) for(auto &i:a) #define all(x) (x).begin(),(x).end() #define allr(x) (x).rbegin(),(x).rend() #define SUM(v) accumulate(all(v), 0LL) #define MIN(v) *min_element(all(v)) #define MAX(v) *max_element(all(v)) #define lb(c, x) distance((c).begin(), lower_bound(all(c), (x))) #define ub(c, x) distance((c).begin(), upper_bound(all(c), (x))) #define pii pair #define pll pair #define pb push_back #define eb emplace_back #define ff first #define ss second #define vi vector #define vll vector #define vvll vector> #define vc vector #define vvi vector> #define vec(type, name, ...) vector name(__VA_ARGS__) #define VEC(type, name, size) \ vector name(size); \ IN(name) int scan() { return getchar(); } void scan(int &a) { cin >> a; } void scan(long long &a) { cin >> a; } void scan(char &a) { cin >> a; } void scan(double &a) { cin >> a; } void scan(string &a) { cin >> a; } template void scan(pair &p) { scan(p.first), scan(p.second); } template void scan(vector &); template void scan(vector &a) { for(auto &i : a) scan(i); } template void scan(T &a) { cin >> a; } void IN() {} template void IN(Head &head, Tail &...tail) { scan(head); IN(tail...); } template void print(const T &a) { cout << a; } void OUT() { cout << endl; } template void OUT(const Head &head, const Tail &...tail) { print(head); if(sizeof...(tail)) cout << ' '; OUT(tail...); } #define vv(type, name, h, ...) vector> name(h, vector(__VA_ARGS__)) #define VV(type, name, h, w) \ vector> name(h, vector(w)); \ IN(name) #define vvv(type, name, h, w, ...) vector>> name(h, vector>(w, vector(__VA_ARGS__))) #define vvvv(type, name, a, b, c, ...) \ vector>>> name(a, vector>>(b, vector>(c, vector(__VA_ARGS__)))) template using min_priority_queue = priority_queue, greater>; template pair operator-(const pair &x, const pair &y) { return pair(x.ff - y.ff, x.ss - y.ss); } template pair operator+(const pair &x, const pair &y) { return pair(x.ff + y.ff, x.ss + y.ss); } template pair operator&(const pair &l, const pair &r) { return pair(max(l.ff, r.ff), min(l.ss, r.ss)); } template vector &operator--(vector &v) { fore(e, v) e--; return v; } template vector operator--(vector &v, int) { auto res = v; fore(e, v) e--; return res; } template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } #define UNIQUE(x) sort(all(x)), x.erase(unique(all(x)), x.end()) //座標圧縮 template void zip(vector &x) { vector y = x; UNIQUE(y); for(int i = 0; i < x.size(); ++i) { x[i] = lb(y, x[i]); } } template T ceil(T x, T y) { assert(y >= 1); return (x > 0 ? (x + y - 1) / y : x / y); } template T floor(T x, T y) { assert(y >= 1); return (x > 0 ? x / y : (x + y - 1) / y); } long long POW(long long x, int n) { long long res = 1LL; for(; n; n >>= 1, x *= x) if(n & 1) res *= x; return res; } //0^n=0 long long modpow(long long a, long long n, long long mod) { a%=mod; assert(a!=0||n!=0); if(a==0)return 0; long long res = 1; while (n > 0) { if (n & 1) res = res * a % mod; a = a * a % mod; n >>= 1; } return res; } //return 0<=a&&a> x; return x; } ll lin() { unsigned long long x; cin >> x; return x; } long long sqrtll(long long x) { assert(x >= 0); long long rev = sqrt(x); while(rev * rev > x) --rev; while((rev+1) * (rev+1)<=x) ++rev; return rev; } int logN(long long n){ int ret=1; while((1LL<::max() / 2; const long long INFL = numeric_limits::max() / 2; #define inf INFINITY template void debug(vector a){ rep(i,0,(int)a.size()){ cout< class modint { using u64 = std::uint_fast64_t; public: u64 a; constexpr modint(const u64 x = 0) noexcept : a(x % Modulus) {} constexpr u64 &val() noexcept { return a; } constexpr const u64 &val() const noexcept { return a; } constexpr modint operator+(const modint rhs) const noexcept { return modint(*this) += rhs; } constexpr modint operator-(const modint rhs) const noexcept { return modint(*this) -= rhs; } constexpr modint operator*(const modint rhs) const noexcept { return modint(*this) *= rhs; } constexpr modint operator/(const modint rhs) const noexcept { return modint(*this) /= rhs; } constexpr modint &operator+=(const modint rhs) noexcept { a += rhs.a; if (a >= Modulus) { a -= Modulus; } return *this; } constexpr modint &operator-=(const modint rhs) noexcept { if (a < rhs.a) { a += Modulus; } a -= rhs.a; return *this; } constexpr modint &operator*=(const modint rhs) noexcept { a = a * rhs.a % Modulus; return *this; } constexpr modint &operator/=(modint rhs) noexcept { u64 exp = Modulus - 2; while (exp) { if (exp % 2) { *this *= rhs; } rhs *= rhs; exp /= 2; } return *this; } friend bool operator==(const modint& a,const modint& b) { return a.val()==b.val(); } friend bool operator!=(const modint& a,const modint& b) { return a.val()!=b.val(); } }; using mint9=modint<998244353>; using mint1=modint<1000000007>; constexpr pii dx4[4] = {pii{-1, 0}, pii{0, 1}, pii{1, 0}, pii{0, -1}}; constexpr pii dx8[8] = {{1, 0}, {1, 1}, {0, 1}, {-1, 1}, {-1, 0}, {-1, -1}, {0, -1}, {1, -1}}; constexpr pii dx[8] = { {-1, 0}, {0, -1}}; #define el "\n" #define endl "\n" #define fastio std::cin.sync_with_stdio(false);std::cin.tie(nullptr); vector > prime_factorize(long long N) { vector > res; ll cnt=0; for (long long a = 2; a * a <= N; ++a) { if (N % a != 0) continue; long long ex = 0; // 指数 // 割れる限り割り続ける while (N % a == 0) { ++ex; N /= a; } cnt+=ex*(a+1); // その結果を push res.push_back({a, ex}); if(cnt>=200000){ OUT(-1);exit(0); } } // 最後に残った数について if (N != 1) res.push_back({N, 1}); return res; } int main(){ //fastio //cout< pf=prime_factorize(x); vector ans; vc c(300000); int cur=0; int pre=-1; rep(i,0,pf.size()){ rep(j,0,pf[i].ss){ int p=++cur; c[p]='b'; rep(k,0,pf[i].ff){ int now=++cur; ans.pb({p,cur}); c[now]='g'; } if(pre!=-1){ ans.pb({pre,p}); } pre=p; } } if(cur>=200000){ OUT(-1); return 0; }else{ OUT(cur); rep(i,0,cur-1){ OUT(ans[i].ff,ans[i].ss); } rep(i,0,cur){ cout<