#include<bits/stdc++.h>

using namespace std;
#define int long long

const int maxn = 1e6 + 155;
int a[maxn], m, len, dt, b[20],c[maxn];
__int128 Q[30];
char s[maxn], t[maxn];
void solve(){
  cin>>s>>m;
  len = strlen(s);
  int Res = 0;
  for(int i=0;i<=len+100;++i)a[i]=c[i]=0;
  for(int i = 1; i <= len; ++i){
    Res = (Res * 10 + (s[i-1] ^ 48)) % m;
    a[len-i]=s[i-1]-'0';
  }
  a[0]++;
  for(int i=0;i<len;++i)if(a[i]>=10)a[i]-=10,a[i+1]++;
  if(a[len])++len;
  //for(int i=0;i<len;++i)cout<<a[i]<<' ';cout<<endl;
  int tmp=m,cnt=0,flag=0;
  while(tmp)b[cnt++]=tmp%10,tmp/=10;
  for(int i=cnt;i<=len;++i){
    int F=1;
    for(int j=i-cnt;j<i;++j)if(a[j]!=b[j-(i-cnt)])F=0;
    if(F)flag=1;
  }
  if(flag){
    for(int i=len-1;i>=0;--i)cout<<a[i];cout<<'\n';
    return;
  }
  __int128 sum=0,S=m,res=m-Res;
  flag=0;
  for(int i=0;i<cnt;++i)sum=sum+a[i]*Q[i];
  for(int i=cnt;i<cnt*2;++i){
    __int128 ans=S-sum;
    if(i==cnt&&ans>=0)flag=ans;
    //cout<<(int)S<<' '<<(int)sum<<'\n';
    if(ans<0)ans+=Q[i];
    res=min(res,ans+1);
    sum=sum+a[i]*Q[i];
    S*=10;
  }
  if(flag==0||flag>=res){
    a[0]+=res-1;
    for(int i=0;i<len;++i)if(a[i]>=10)a[i]-=10,a[i+1]++;
    while(a[len])++len;
    for(int i=len-1;i>=0;--i)cout<<a[i];cout<<'\n';
    return;
  }
  else{
    for(int i=0;i<len;++i)c[i]=a[i];
    a[cnt]++;
    for(int i=0;i<len;++i)if(a[i]>=10)a[i]-=10,a[i+1]++;
    if(a[len])++len;
    //for(int i=0;i<cnt;++i)a[i]=0;
    int Flag=0;
    for(int i=cnt;i<=len;++i){
      int F=1;
      for(int j=i-cnt;j<i;++j)if(a[j]!=b[j-(i-cnt)])F=0;
      if(F)Flag=1;
    }
    if(Flag){
      for(int i=len-1;i>=0;--i)cout<<a[i];cout<<'\n';
      return;
    }
    else{
      c[0]+=res-1;
      for(int i=0;i<len;++i)if(c[i]>=10)c[i]-=10,c[i+1]++;
      while(c[len])++len;
      for(int i=len-1;i>=0;--i)cout<<c[i];cout<<'\n';
      return;
    }
  }
}

signed main(){
  ios::sync_with_stdio(0);
  Q[0]=1;
  for(int i=1;i<30;++i)Q[i]=Q[i-1]*10;
  int t; cin>>t;
  for(int i = 1; i <= t; ++i)solve();
  return 0;
}