program pr;
var N,result,i:integer;
begin
readln(N);
result:=1;
for i:=1 to N do result:=result*i;
writeln(result);
end.
program pr;
var N,result,i:integer;
begin
readln(N);
result:=1;
for i:=1 to N do result:=result*i;
writeln(result);
end.