#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pi (4*atan(1.0))
#define eps 1e-14
const int N=2e5+10,M=4e6+10,inf=1e9+10,MOD=1000;
const ll INF=1e18+10;
int a[100]={1,15,150,750,7500,75000,750000,7500000,75000000,750000000};
int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        int k,m;
        scanf("%d%d",&k,&m);
        if(k==2)
            printf("%d\n",((m-1)/4*5+1)*a[k]+((m-1)%4)*a[k]);
        else
            printf("%d\n",((m-1)/9*10+1)*a[k]+((m-1)%9)*a[k]);
    }
    return 0;
}