WRITE A PLSQL PROGRAM INPUT ANY STRING AND PRINT ITS ACRONYM?

DECLARE
STR1 VARCHAR2(100):='&STR1';
STR2 VARCHAR2(100);
BEGIN
STR2:=STR2||UPPER(SUBSTR(STR1,1,1))||'.';
FOR I IN 2..LENGTH(STR1) LOOP
IF((SUBSTR(STR1,I,1):=' ') AND (SUBSTR(STR1,I+1,1)!=' ')) THEN
STR2:=STR2||UPPER(SUBSTR(STR1,I+1,1))||'.';
END IF;
END LOOP;
DBMS_OUTPUT.PUT_LINE('THE ACRONYM IS'||' '||STR2);
END;