%scan function

[marathon2]

I am trying to set start_yr to be 2021 and end_yr to be 2022, using the macro below. I am a beginner in SAS programming language. Can someone help? 

%macro storms(yr);
%let start_yr = %scan(&yr,1);

%let end_yr = %scan(&yr,2);
%put &=start_yr;

%put &=end_yr;
%mend storms;

Edit:

%storms(2021 2022)

[ballardw]

Macro calls start with %.

So as a minimum you need to use

%storms(2021 2022)