ModInt.cpp

#include<bits/stdc++.h>
using namespace std;

const long long P = 1e9 + 7;

// assume -P <= x < 2 * P
long long norm(long long x) {
    if(x < 0) x += P;
    if(x >= P) x -= P;
    return x;
}

template<typename T>
T binpow(T a, long long b) {
    T res = 1;
    while(b > 0) {
        if(b & 1) res = (res * a);
        a = (a * a);
        b >>= 1;
    }
    return res;
}

struct Z {
    long long x;
    Z(long long x = 0) : x(norm(x % P)) {}
    long long val() const {
        return x;
    }
    Z operator-() const {
        return Z(norm(P - x));
    }
    Z inv() const {
        assert(x != 0);
        return binpow(*this, P - 2);
    }
    Z &operator*=(const Z &rhs) {
        x = (x * rhs.x) % P;
        return *this;
    }
    Z &operator+=(const Z &rhs) {
        x = norm(x + rhs.x);
        return *this;
    }
    Z &operator-=(const Z &rhs) {
        x = norm(x - rhs.x);
        return *this;
    }
    Z &operator/=(const Z &rhs) {
        return *this *= rhs.inv();
    }
    friend Z operator*(const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res *= rhs;
        return res;
    }
    friend Z operator+(const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res += rhs;
        return res;
    }
    friend Z operator-(const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res -= rhs;
        return res;
    }
    friend Z operator/(const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res /= rhs;
        return res;
    }
    friend istream &operator>>(istream &is, Z &a) {
        long long v;
        is >> v;
        a = Z(v);
        return is;
    }
    friend ostream &operator<<(ostream &os, const Z &a) {
        return os << a.val();
    }
};

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