import java.io.*;
import java.util.*;
import java.util.concurrent.*;
public class Main {
int T
= Integer.
parseInt(st.
nextToken());
info
[0] = new ArrayList
<>(Arrays.
asList(0)); info
[1] = new ArrayList
<>(Arrays.
asList(1)); info
[2] = new ArrayList
<>(Arrays.
asList(2,
4,
8,
6)); info
[3] = new ArrayList
<>(Arrays.
asList(3,
9,
7,
1)); info
[4] = new ArrayList
<>(Arrays.
asList(4,
6)); info
[5] = new ArrayList
<>(Arrays.
asList(5)); info
[6] = new ArrayList
<>(Arrays.
asList(6)); info
[7] = new ArrayList
<>(Arrays.
asList(7,
9,
3,
1)); info
[8] = new ArrayList
<>(Arrays.
asList(8,
4,
2,
6)); info
[9] = new ArrayList
<>(Arrays.
asList(9,
1));
for (int test = 1; test <= T; test++) {
int a
= Integer.
parseInt(st.
nextToken()); int b
= Integer.
parseInt(st.
nextToken());
int idx = -1;
if(b % info[a % 10].size() == 0) {
idx = info[a % 10].size() - 1;
} else {
idx = b % info[a % 10].size() - 1;
}
bw.write(info[a % 10].get(idx) + "\n");
}
bw.flush();
br.close();
bw.close();
}
}
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