program ho_tro;
uses crt;
var s,n,i: integer;
begin
clrscr;
writeln(' nhap so n:'); readln(n);
s:=0;
for i:=1 to n do
s:=s+i;
writeln(' tong la:',n);
readln;
program ho_tro;
uses crt;
var n1,n,i: integer;
begin
clrscr;
writeln(' nhap n:'); readln(n);
n1:=1;
for i:=1 to n do
n1:=n1*i;
writeln(' ket qua cua tich la:',n1);
readln;
end.
1:
uses crt;
var s,i,n:integer;
begin
clrscr;
write('n='); readln(n);
s:=0;
for i:=1 to n do
s:=s+i;
writeln('tong cua ',n,' so tu nhien dau tien la: ',s);
readln;
end.
2:
uses crt;
var n,i:integer;
gt:longint;
begin
clrscr;
write('nhap n='); readln(n);
gt:=1;
for i:=1 to n do
gt:=gt*i;
writeln(n,'!'=',gt);
readln;
end.