#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define db double
#define in inline
#define ld long db
namespace fast_io
{
	char buf[1<<12],*p1=buf,*p2=buf,sr[1<<23],z[23],nc;int C=-1,Z=0,Bi=0,ny;
	in char gc() {return p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<12,stdin),p1==p2)?EOF:*p1++;}
	in ll read()
	{
		ll x=0;ny=1;while(nc=gc(),(nc<48||nc>57)&&nc!=EOF)if(nc==45)ny=-1;Bi=1;if(nc<0)return nc;
		x=nc-48;while(nc=gc(),47<nc&&nc<58&&nc!=EOF)x=(x<<3)+(x<<1)+(nc^48),Bi++;return x*ny;
	}
	in db gf() {int a=read(),y=ny,b=(nc!='.')?0:read();return (b?a+(db)b/pow(10,Bi)*y:a);}
	in int gs(char *s) {char c,*t=s;while(c=gc(),c<=32);*s++=c;while(c=gc(),c>32)*s++=c;return s-t;}
	in void ot() {fwrite(sr,1,C+1,stdout);C=-1;}
	in void flush() {if(C>1<<22) ot();}
	template <typename T>
	in void write(T x,char t)
	{
		int y=0;if(x<0)y=1,x=-x;while(z[++Z]=x%10+48,x/=10);
		if(y)z[++Z]='-';while(sr[++C]=z[Z],--Z);sr[++C]=t;flush();
	}
	in void write(char *s) {int l=strlen(s);for(int i=0;i<l;i++)sr[++C]=*s++;sr[++C]='\n';flush();}
}
using namespace fast_io;
const int N=1e5+5;
int T,n,k;
ll pw[20];
char s[20],t[20];
void upd(int l,int r)
{
	//cout<<"updated "<<l<<" "<<r<<endl;
	t[r]='9'-s[r]+'0'+1,k--;
	for(int i=l;i<r;i++)
	t[i]='9'-s[i]+'0',k--;
	if(l>1&&t[l-1]>'0') t[l-1]--;
	//puts(t+1);
}
void output(int l,int r)
{
	for(int i=l;i<=n;i++) if(!t[i]) t[i]='0';
	while(t[l]=='0') l++;
	puts(t+l);
}
int main()
{
	pw[0]=1;for(int i=1;i<20;i++) pw[i]=pw[i-1]*10;
	T=read();
	while(T--)
	{
		memset(s,0,sizeof(s)),memset(t,0,sizeof(t));
		n=gs(s+1),k=read();
		if(!k)
		{
			int op=0;
			for(int i=n;i;i--) if(s[i]^'9')
			{
				printf("%lld\n",pw[n-i]);
				op=1;break;
			}
			if(!op) printf("%lld\n",pw[n]);
			continue;
		}
		int r=n;while(s[r]=='0') r--;
		int l=r-k+1;
		if(l<1)
		{
			for(int i=r+1;i<=n;i++) t[i]='0';
			upd(1,r);
			while(k--) putchar('9');
			puts(t+1);
			continue;
		}
		if(l==1||s[l-1]^'9')
		{
			upd(l,r);output(l,r);
			continue;
		}
		while(l>1&&s[l-1]=='9') l--;
		//dfs(l,r);
		//cout<<l<<":"<<r<<"!\n";
		while(k)
		{
			int i=r-k+1;
			if(s[i-1]^'9') {upd(i,r);continue;}
			while(s[i-1]=='9') i--;
			int j=i+1;
			while(s[j]=='9'||s[j]=='0'&&j<r) j++;
			//cout<<i<<":"<<j<<" "<<k<<"!\n";
			if(j-i+1<=k) upd(i,j),i=j;
			else
			{
				int to=i+k-1;
				//cout<<i<<"::"<<to<<endl;
				while(s[to]=='0') to--;
				//cout<<i<<"::"<<to<<endl;
				if(i>to) continue;
				upd(i,to),i=to;
			}
		}
		output(l,r);
	}
    return 0;
}
/*
2
999901 5
919991 6

1
999990000099999 10
---
10000000001
---
10999910000
*/