Recognize pattern

[yabwon]

Zero at the RightEnd of the string or at the LeftEnd? 

1010101 

1010100 

0101010 

0101011

Bart

[yabwon]

BTW. your data step with example cuts your data in half...

Should be:

input X $ 20.;

or something like that....

Bart

[yabwon]

But remember if the length of X exceeds capabilities of:

 mod(X,2)

results won't be the same,

to be clear you can replace MOD() with

 char(length(X)) = "1"

to verify if the last character is 1

Bart

[Ronein]

Zero cannot be at right end because right end reflect existing of customers this month and the query check only customers existing this month