get value until get positive value group wise

[thanikondharish]

amt      new_amt
2           2
-3          0
-4          0
5         5(-7)=-2 so should come zero and (-2 remaining value)
6         -2+6=4 (value 4 should come)(until value get positive)
7           7
-4          0
2          -4+2=-2 (negative so value should come 0)

finally

amt        new_amt
2             2
-3           0
-4           0
5            0
6            4
7            7
-4           0
2            0

we have one data like negative and positive values are there if negative value is there then we have to subtract next value until get positive. I have give raw data and final data

[PeterClemmensen]

Do something like this

data have;
input amt;
datalines; 
2    
-3   
-4   
5    
6    
7    
-4   
2    
;

data want(drop = n);
   set have;
   new_amt = amt;
   if new_amt < 0 then do;
      n + new_amt;
      new_amt = 0;
   end;
   if new_amt > 0 & n < 0 then do;
      new_amt = max(0, new_amt + n);
      n = min(n + amt, 0);
   end;
run;

Result:

amt  new_amt 
2    2 
-3   0 
-4   0 
5    0 
6    4 
7    7 
-4   0 
2    0