uses crt;
const fi='songuyen.txt'
var f1:text;
a:array[1..100]of integer;
i,n,t:integer;
begin
clrscr;
assign(f1,fi); reset(f1);
n:=0;
while not eof(f1) do
begin
inc(n);
read(f1,a[n]);
end;
t:=0;
for i:=1 to n do
if a[i]>0 then t:=t+a[i];
writeln(t);
close(f1);
readln;
end.