#include<bits/stdc++.h>
using namespace std;
#define int long long
string s;
int a[1000025],ans;
int b[1000025],lb;
int M,len,n,sum,lim,m;
bool check()
{
    int now=0;
    for(int i=len;i>=1;i--)
    {
        now=now*10+b[i];
    }
    if(now==m)return 1;
    //cerr<<now<<endl;
    for(int i=len+1;i<=lb;i++)
    {
        now=(now-b[i-len])/10;
        now+=b[i]*(M/10);
        if(now==m)return 1;
    }
    return 0;
}
void maintain(int x)
{
    for(int i=1;i<=lb;i++)
        b[i]=0;
    for(int i=len+1;i<=n;i++)
        b[i]=a[i];
    b[1]=x;
    lb=n;
    for(int i=1;i<=lb;i++)
    {
        b[i+1]+=b[i]/10;
        b[i]%=10;
    }
    while(b[lb+1])
    {
        lb++;
        b[lb+1]+=b[lb]/10;
        b[lb]%=10;
    }
}
void solve(void)
{
    cin>>s>>m;
    M=1;len=0;lim=0;
    while(M<=m)M*=10,len++;
    n=s.size(),sum=0;
    for(int i=n-1;i>=0;i--)
    {
        sum=(sum*10+s[i]-'0')%m;
        a[n-i]=s[i]-'0';
    }
    ans=m-sum-1;
    for(int i=1;i<=18;i++)
        a[n+i]=0;
    a[1]++;
    for(int i=1;i<=n;i++)
    {
        a[i+1]+=a[i]/10;
        a[i]%=10;
    }
    if(a[n+1])n++;
    for(int i=1;i<=n;i++)
        b[i]=a[i];
    lb=n;
    if(check())
        ans=0;
    lim=0;
    for(int i=len;i>=1;i--)
        lim=lim*10+a[i];
    int t=m;
    for(int i=1;i<=len;i++)
    {
        b[i]=0;
    }
    for(int i=0;i<=len;i++)
    {
        if(t<lim)
        {
            int d=M+t-lim;
            if(d>=ans)continue;
            maintain(t);
            if(check())ans=d;
        }
        else
        {
            int d=t-lim;
            //cerr<<d<<endl;
            if(d>=ans)continue;
            maintain(t);
            //for(int i=1;i<=lb;i++)
            //    cout<<b[i]<<" ";
            //cout<<endl;
            if(check())ans=d;
        }
        t=t*10%M;
    }
    a[1]+=ans;
    for(int i=1;i<=n;i++)
    {
        a[i+1]+=a[i]/10;
        a[i]%=10;
    }
    while(a[n+1])
    {
        n++;
        a[n+1]+=a[n]/10;
        a[n]%=10;
    }
    for(int i=n;i>=1;i--)
        cout<<a[i];
    cout<<'\n';
    for(int i=1;i<=lb;i++)
        b[i]=0;
    for(int i=1;i<=n;i++)
        a[i]=0;
    lb=0;
}
signed main(void)
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t=1;
    cin>>t;
    while(t--)
    {
        solve();
    }
    return 0;
}