program hello;
var i,x,y,y1:integer;
begin
y:=1;
y1:=0;
write('Введи число ');
read(x);
while x>=1 do
for i:=1 to x do
y:=y*i;
end;
y1:=y1+y;
x:=x-1;
write(y1:2);
readln;
end.