data set

1  3  5  1  4
1  5 23  6  1
2  4 17  3 1O
2  6  3  5  2
3  4 12  6  2
3  3 20 21  8
4  6 12 12 16
4  5  6  4 -9
 

errors

1  3  5  1  4
1  5 23  6  1
2  4 17  3 1O {the number 1 followed by the letter O}
2  6  3  5  2
3  4 12  6  2
3  3 20 21  8 {transposed; should be 12}
4  6 12 12 16
4  5  6  4 -9