var a,b,c,max:real;
begin
readln(a,b,c);
max:=a;
if max<b then max:=b;
if max<c then max:=c;
max:=max-5;
write(max);
end.
var a,b,c,max:real;
begin
readln(a,b,c);
max:=a;
if max<b then max:=b;
if max<c then max:=c;
max:=max-5;
write(max);
end.