program xcoins;
var
a:array[5..10] of longint;
n:int64;
begin
assign(input,'xcoins.in');
assign(output,'xcoins.out');
reset(input);
rewrite(output);
readln(n);
a[5]:=1;
a[6]:=6;
a[7]:=3;
a[8]:=4;
a[9]:=3;
a[10]:=2;
if (n<11) then
writeln(a[n])
else
if n div 5=0 then writeln(n div 5)
else writeln(n div 5+(n mod 5+1) mod 2 + 1);
close(input);
close(output);
end.