#include<iostream>

#include<cstdio>

#include<algorithm>

#include<cstdlib>

#include<cstring>

#include<string>

#include<cmath>

#include<map>

#include<set>

#include<vector>

#include<queue>

#include<bitset>

#include<ctime>

#include<deque>

#include<stack>

#include<functional>

#include<sstream>

//#include<cctype>

//#pragma GCC optimize(2)

using namespace std;

#define maxn 1000005

#define inf 0x7fffffff

//#define INF 1e18

#define rdint(x) scanf("%d",&x)

#define rdllt(x) scanf("%lld",&x)

#define rdult(x) scanf("%lu",&x)

#define rdlf(x) scanf("%lf",&x)

#define rdstr(x) scanf("%s",x)

typedef long long  ll;

typedef unsigned long long ull;

typedef unsigned int U;

#define ms(x) memset((x),0,sizeof(x))

const long long int mod = 1e9 + 7;

#define Mod 1000000000

#define sq(x) (x)*(x)

#define eps 1e-4

typedef pair<int, int> pii;

#define pi acos(-1.0)

//const int N = 1005;

#define REP(i,n) for(int i=0;i<(n);i++)

typedef pair<int, int> pii;

inline ll rd() {

	ll x = 0;

	char c = getchar();

	bool f = false;

	while (!isdigit(c)) {

		if (c == '-') f = true;

		c = getchar();

	}

	while (isdigit(c)) {

		x = (x << 1) + (x << 3) + (c ^ 48);

		c = getchar();

	}

	return f ? -x : x;

}

ll gcd(ll a, ll b) {

	return b == 0 ? a : gcd(b, a%b);

}

int sqr(int x) { return x * x; }

/*ll ans;

ll exgcd(ll a, ll b, ll &x, ll &y) {

	if (!b) {

		x = 1; y = 0; return a;

	}

	ans = exgcd(b, a%b, x, y);

	ll t = x; x = y; y = t - a / b * y;

	return ans;

}

*/

int T;

int K, M;

ll maxx[21];

int dig[2100];

int a[2000];

ll qpow(int x) {

	ll ans = 1;

	for (int i = 1; i <= x; i++)ans *= 10;

	return ans;

}

int main() {

	//ios::sync_with_stdio(0);

	cin >> T;

	maxx[0] = 1;

	for (int i = 1; i <= 20; i++)maxx[i] = maxx[i - 1] * 10;

	while (T--) {

		rdint(K); rdint(M);

		bool fg = 0;

		for (int i = 0; i < 19; i++) {

			if (K == maxx[i] && M != i + 1) {

				cout << 0 << endl;

				fg = 1; break;

			}

		}

		if (fg)continue;

		ll tp = K; int tot = 0; ms(dig);

		while (tp) {

			int y = tp % 10;

			dig[++tot] = y; tp /= 10;

		}

		for (int i = 1; i <= tot; i++) {

			a[i] = dig[tot - i + 1];

		}

		tp = 1; ll reg = 0; ll tmp = 0;

		for (int i = 1; i <= tot; i++) {

			reg = reg * 10ll + a[i];

			tmp += (reg - qpow(i - 1) + 1);

		}

		if (tmp > M) {

			cout << 0 << endl; continue;

		}

		if (tmp == M) { cout << K << endl; continue; }

		tp = 1; M -= tmp;

		ll number = 1ll * reg * 10 - qpow(tot + tp - 1);

		while (number < M) {

			M -= number; number *= 10; tp++;

		}

		cout << qpow(tp + tot - 1) + M - 1 << endl;

	}

	return 0;

}