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d.cpp
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#include <bits/stdc++.h>
#define endl '\n'
#define eat cin
#define moo cout
#define int long long
using namespace std;
int MOD = 1e9+7;
int M, X[100001], I[100001];
vector<int> F[100001], P[100001];
int op[100001];
int inv(int x){
int e = MOD-2;
int ans = 1;
while(e){
if(e & 1){
ans = ans * x % MOD;
}
e >>= 1;
x = x * x % MOD;
}
return ans;
}
int32_t main(){
eat.tie(0) -> sync_with_stdio(0);
eat >> M;
for(int i = 1; i <= M; i++){
for(int j = i; j <= M; j += i){
F[j].push_back(i);
}
if((int)F[i].size() == 2){
for(int j = i; j <= M; j += i){
P[j].push_back(i);
}
}
}
for(int i = 1; i <= M; i++){
I[i] = inv(i);
}
X[1] = 1;
for(int i = 2; i <= M; i++){
for(int j : F[i]) op[j] = 0;
for(int j : F[i]){
int a = i/j;
int mx = M/j;
int sz = P[a].size();
int sum = 0;
for(int k = 1; k < (1<<sz); k++){
int cur = 1;
for(int l = 0; l < sz; l++){
if((k>>l) & 1){
cur *= P[a][l];
}
}
sum += mx/cur * ((__builtin_popcount(k) & 1) ? 1 : -1);
}
op[j] = mx - sum;
/*op[j] = (op[j] + M/j) % MOD;
for(int k : F[j]){
int dv = j/k;
if(dv == 1 || (int)F[dv].size() > 2) continue;
op[k] = (op[k] - M/j) % MOD;
moo << i << ' ' << j << ' ' << k << endl;
}*/
}
/*moo << i << ' ';
for(int j : F[i]){
moo << j << '/' << op[j] << '|';
}moo << endl;*/
X[i] = M;
for(int j : F[i]){
if(i == j) break;
X[i] = (X[i] + op[j] * X[j]) % MOD;
}
X[i] = X[i] * I[M-op[i]] % MOD;
}
int ans = 0;
for(int i = 0; i <= M; i++){
ans = (ans + X[i]) % MOD;
//moo << i << ' ' << X[i] << endl;
}
ans = (ans * I[M]) % MOD;
moo << ans << endl;
}