program Zadacha8;
{$APPTYPE CONSOLE}
var i,k,l,n,s:integer;
begin
writeln('Skilki riadiv babus');
readln(n);
writeln('Skilki riadiv z komp"yuteramy');
readln(k);
writeln('Skilki komp"yuteriv v riadi');
readln(l);s:=0;
for i:=1 to n do
s:=s+i;
if s>l*k then
writeln('Na vsih ne vystachyt') else
if s=l*k then
writeln('Vilnyh mist ne zalyshylosia') else
writeln('Vilnyh mist e ',l*k-s);
readln;
end.