In a fuller context:

    if(p_wn=='hy'){if(wn==1)pwn='1-ին շաբաթ';else pwn=wn+'-րդ շաբաթ'}

So if the locale is "hy" (Armenian), and the week number is one, set the string to "1st week", else set the string to "#th week" (both in Armenian).

Unlike English, which also has exceptions for "2nd" and "3rd", Armenian only uses a different suffix for "1st".