{programmer:mogtaba amirzade 
url http:\\www.ifjam.com
}
var
i,n:inteGer;
S,x:real;
BEGIN
assign(input,'a:\programs\inp4.dat');
reset(input);
assign(output,'a:\programs\outp4.dat');
rewrite(output);
S:=0;
I:=1;
WRITE('ENTER NAMBER>');
READLN(N);
IF N=0 THEN
s:=0
ELSE
BEGIN
REPEAT
WRITELN('ENTER X',I);
READLN(X);
S:=S+X;
I:=I+1;
UNTIL I>N;
END;
WRITELN(S:1);
READLN;
READLN
END.