Two columns A and B: Column A have repeated ids and column B has different values for each corresponding repeated value. I would like to read every uniq value from Column A with only the first hit from column B

File\_B.txt

```

A 1
A 2
B 3
B 2
B 4
C 1
C 5
D 4
D 3
E 2

```

Output:

```

A 1
B 3
C 1
D 4
E 2

```