蒟蒻在写多项式乘法时遇到一个奇怪的问题：本地和学校OJ都可编译，但在洛谷上一直提示“编译失败”，代码如下：

#include <bits/stdc++.h>
#define clr(a, n) memset(a, 0, sizeof(int) * n)
#define cpy(a, b, n) memcpy(a, b, sizeof(int) * n)

typedef long long ll;
typedef unsigned long long ull;
typedef double f64;
typedef long double f128;

const int MAXN = 2000005, MOD = 998244353, _G = 3;
int read()
{
	int s = 0, f = 1;
	char ch = getchar();
	while (!(ch >= '0' && ch <= '9'))
	{
		if (ch == '-')
			f = -1;
		ch = getchar();
	}
	while (ch >= '0' && ch <= '9')
		s = (s << 3) + (s << 1) + (ch ^ 48), ch = getchar();
	return s * f;
}
void pttimes(int *f, int *g, int len)
{
	for (int i = 0; i < len; i++)
		f[i] = 1ll * f[i] * g[i] % MOD;
}
int tr[MAXN << 1], curn;
void tsetup(int n)
{
	if (curn == n)
		return ;
	curn = n;
	for (int i = 0; i < n; i++)
		tr[i] = tr[i >> 1] >> 1 | ((i & 1) ? (n >> 1) : 0);
}
ll fpow(ll x, ll y)
{
	ll res = 1;
	for (; y; y >>= 1, x = x * x % MOD)
		if (y & 1)
			res = res * x % MOD;
	return res;
}
inline ll inv(int x)
{
	return fpow(x, MOD - 2);
}
const int invG = inv(_G);
void NTT(int *g, bool fl, int n)
{
	tsetup(n);
	static ull f[MAXN << 1], w[MAXN << 1] = {1};
	for (int i = 0; i < n; i++)
		f[i] = (((ll)MOD << 5) + g[tr[i]]) % MOD;
	for (int len = 1; len < n; len <<= 1)
	{
		ull rt = fpow(fl ? _G : invG, (MOD - 1) / (len << 1));
		for (int i = 1; i < len; i++)
			w[i] = w[i - 1] * rt % MOD;
		for (int p = 0; p < n; p += (len << 1))
			for (int cur = 0; cur < len; cur++)
			{
				int t = w[cur] * f[p | len | cur] % MOD;
				f[p | len | cur] = f[p | cur] + MOD - t;
				f[p | cur] = f[p | cur] + t;
			}
		if (len == (1 << 10))
			for (int i = 0; i < n; i++)
				f[i] %= MOD;
	}
	if (fl)
		for (int i = 0; i < n; i++)
			g[i] = f[i] % MOD;
	else
	{
		ull invn = inv(n);
		for (int i  =0; i < n; i++)
			g[i] = f[i] % MOD * invn % MOD;
	}
}
void polytimes(int *f, int *g, int len, int lim)
{
	static int tmp[MAXN << 1];
	int n = 1;
	for (; n < (len << 1); n <<= 1) ;
	clr(tmp, n), cpy(tmp, g, n);
	NTT(f, 1, n), NTT(tmp, 1, n);
	pttimes(f, tmp, n), NTT(f, 0, n);
	clr(f + lim, n - lim), clr(tmp, n);
}
int a[MAXN << 2] = {0}, b[MAXN << 2] = {0}, n = 0, m = 0;
void read(int a[], int &n)
{
	char ch = getchar();
	while (!(ch >= '0' && ch <= '9'))
		ch = getchar();
	while (ch >= '0' && ch <= '9')
		a[n++] = ch -'0', ch = getchar();
	std::reverse(a, a + n);
}
int main()
{
	read(a, n), read(b, m);
	polytimes(a, b, std::max(n, m), n + m);
	n += m;
	for (; a[n] == 0; n--) ;
	for (int i = 0; i <= n; i++)
	{
		if (a[i] / 10 && n == i)
			n++;
		a[i + 1] += a[i] / 10, a[i] %= 10;
	}
	for (; ~n; n--)
		printf("%d", a[n]);
	#ifndef ONLINE_JUDGE
		system("pause");
	#endif
	return 0;
}