program to add integers from 1 to n.txt

.program to add integers from 1 to n (inclusive)
.using the formula: n(n+1)/2
.2345678901234567890123
SUM      START   1000
         LDA     N
         ADD     ONE
         MUL     N
         DIV     TWO
         STA     ANS
N        WORD    4
ONE      WORD    1
TWO      WORD    2
ANS      RESW    1
         END     SUM