program slatkisi;
var a,b,c,d:longint;
st1,st2:string;
begin
readln(a);
readln(b);
d:=5;
for c:=2 to b do d:=d*10;
str(a,st1);
c:=length(st1);
c:=c-b; st2:=copy(st1,c+1,b);
val(st2,c);
if c<d then a:=a-c
else a:=a-c+(2*d);
writeln(a);
end.