#define _CRT_SECURE_NO_WARNINGS
#include <algorithm>
#include <vector>
#include <cstdio>
#include <cstring>
#include <cmath>

using namespace std;
#define forn(i, n) for (int i = 0; i < (n); ++i)
typedef long long ll;
//typedef complex<double> base;
struct base
{
	double real;
	double imag;
	base() {}
	base(const double real, const double imag) : real(real), imag(imag) {};
	base operator + (const base & r) const {
		return base(real + r.real, imag + r.imag);
	}
	base operator - (const base & r) const {
		return base(real - r.real, imag - r.imag);
	}
	base operator * (const base & r) const {
		return base(real * r.real - imag * r.imag,
					real * r.imag + imag * r.real);
	}
};

const double pi = 2 * acos(0);
const int MAXN = (int)3e6 + 10;
char a[MAXN];
char b[MAXN];
const int systpow = 5;
const int syst = pow(10, systpow) + 0.5;
base A[MAXN];
base B[MAXN];
base ww[MAXN];
int ans[MAXN * 2];



inline void fft(base* a, const int n, const bool invert)
{
	for (int i = 1; i < n; ++i)
	{
		int j = 0;
		for (int bit = 1, bitr = (n >> 1); bit < n; bit <<= 1, bitr >>= 1)
			if (i & bit)
				j |= bitr;
		if (i < j) swap(a[i], a[j]);
	}
	for (int i = 0; i < n; ++i)
	{
		ww[i] = base(cos(i * pi * 2 / n), sin(i * pi * 2 / n));
	}

	for (int len = 1; len < n; len <<= 1)
	{
		for (int st = 0; st < n; st += 2 * len){
			//base curw(1, 0);
			for (int j = 0; j < len; ++j){
				base curw = ww[1LL * j * n / 2 / len];
				if (invert) curw = base(curw.real, -curw.imag);

				base l = a[st + j];
				base r = a[st + len + j] * curw;
				a[st + j] = l + r;
				a[st + len + j] = l - r;
			}
		}
	}
	if (invert) for (int i = 0; i < n; ++i)
	{
		a[i].real /= n;
		a[i].imag /= n;
	}
}



int main()
{
	//ios_base::sync_with_stdio(false);
	//cin.tie(0);
	int t;
	scanf("%d\n", &t);

	for (int i = 0; i < t; ++i)
	{
		scanf("%s %s", a, b);
		//printf("%s %s\n", a, b);
		int na = strlen(a);
		int nb = strlen(b);
		
		reverse(a, a + na);
		reverse(b, b + nb);
		int n = 1;
		while (n * systpow < na || n * systpow < nb) n <<= 1;
		n <<= 1;

		//A.resize(n); B.resize(n);
		fill(A, A + n, base(0, 0));
		fill(B, B + n, base(0, 0));
		for (int i = 0, pos = 0; i < na; i += systpow, ++pos)
		{
			int cur = 0;
			for (int j = 0, p = 1; j < systpow && i + j < na; ++j, p *= 10)
				cur += (a[i + j] - '0') * p;
			A[pos].real = cur;
		}
		for (int i = 0, pos = 0; i < nb; i += systpow, ++pos)
		{
			int cur = 0;
			for (int j = 0, p = 1; j < systpow && i + j < nb; ++j, p *= 10)
				cur += (b[i + j] - '0') * p;
			B[pos].real = cur;
		}
		fft(A, n, false);
		fft(B, n, false);
		for (int i = 0; i < n; ++i){
			A[i] = A[i] * B[i];
		}
		fft(A, n, true);
		ll add = 0;
		int anssz = 0;
		for (int i = 0; i < n; ++i){
			ll cur = (ll)(A[i].real + 0.5) + add;
			ans[anssz++] = cur % syst;
			add = cur / syst;
		}
		while (anssz > 1 && ans[anssz-1] == 0)
			--anssz;
		reverse(ans, ans + anssz);

		printf("%d", ans[0]);
		for (int i = 1; i < anssz; ++i)
			printf("%05d", ans[i]);
		printf("\n");
	}
	//cout << n * 1LL * (n - 1) / 2 << endl;
	//cout << stupidSolve(s) << endl;*/
	return 0;

}