var a:array [1..1000] of integer;
fac,i,n: integer;
begin
readln(n);
fac:=1;
for i:=1 to n do begin
a[i]:=i;
end;
fac:=fac*a[i];
writeln(fac);
end.
var a:array [1..1000] of integer;
fac,i,n: integer;
begin
readln(n);
fac:=1;
for i:=1 to n do begin
a[i]:=i;
end;
for i:=1 to n do begin
fac:=fac*a[i];
end;
writeln(fac);
end.