#define _CRT_SECURE_NO_WARNINGS
#include<queue>
#include<cmath>
#include<string>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;

const int N=20;
typedef long long ll;
typedef unsigned long long ull;
int len,zero,a[N];
ll n,K,f[N][N][2],base[20];




int main()
{
	int T;
	base[0]=1;
	for(int i=1;i<=18;i++)
		base[i]=base[i-1]*10ull;
	scanf("%d",&T);
	while(T--)
	{
		scanf("%lld%lld",&n,&K);
		len=zero=0;
		while(!(n%10))zero++,n/=10;
		while(n)a[++len]=n%10,n/=10;
		if(!K)
		{
			for(int i=1;i<=len+1;i++)
				if(a[i]<9){ printf("%lld",base[i-1]);break;}
			for(int i=1;i<=zero;i++)
				putchar('0');
			putchar('\n');
			continue;
		}
		memset(f,0x3f,sizeof(f));
		f[len+1][0][0]=f[len+1][0][1]=0;
		for(int i=len;i;i--)
		{

			for(int j=0,lim=min(1ll*len,K);j<=lim;j++)
			{
				f[i][j][0]=min(f[i][j][0],f[i+1][j][0]);
				if(j>0&&a[i]>0)f[i][j][0]=min(f[i+1][j-1][1]+(10-a[i])*base[i-1],f[i][j][0]);
				if(a[i]<9)f[i][j][1]=min(f[i+1][j][0],f[i][j][1]);
				if(j>0)f[i][j][1]=min(f[i+1][j-1][1]+(9-a[i])*base[i-1],f[i][j][1]);
			}
			/*
			cout<<"i "<<i<<endl;
			for(int j=0;j<=K;j++)
				cout<<f[i][j][0]<<" "<<f[i][j][1]<<endl;
			cout<<endl;
			*/
		}
		if(len<K)
		{
			for(int i=len;i<K;i++)
				putchar('9');
			ll tem=f[1][min(1ll*len,K)][0];int anslen=0;
			while(tem)anslen++,tem/=10;
			for(int i=anslen+1;i<=len;i++)
				putchar('0');
		}
		printf("%lld",f[1][min(1ll*len,K)][0]);
		for(int i=1;i<=zero;i++)
			putchar('0');
		putchar('\n');
	}
	return 0;
}