这里的测试点都是 read $0$

#include"bits/stdc++.h"
using namespace std;
#define int long long
#define p 19260817
void read(int& n) {
	n = 0;
	char t;
	while ((t = getchar())>47&&t<58) {
		n *= 10;
		n += (t - 48);
		n %= p;
	}
}
void exgcd(int a, int b, int& x, int& y) {
	if (!b) {
		x = 1, y = 0;
		return;
	}
	exgcd(b, a % b, y, x);
	y -= a / b * x;
}
int gcd_inv(int x, int m) {
	int ans, k;
	exgcd(x, m, ans, k);
	return (ans + m) % m;
}
signed main() {
	int a, b;
	read(a);
	read(b);
	cout << gcd_inv(b, p) * a % p << endl;
}

${\color{red}记录}$

在${\text{洛谷IDE}}$和本地跑都不会输出$0$.

(测试点$1$在本地和$\text{IDE}$上的结果)