{$N+}

var x, y, temp:extended;
    n, l, r, m, sum, res:extended;

function rnd(t:extended):extended;
begin
     if frac(t)>=0.5 then rnd:=trunc(t)+1
                     else rnd:=trunc(t);
end;

begin
     readln(x, y, n);
     l:=10; r:=10*n; x:=x*10; sum:=-1;
     while l<=r do begin
           m:=trunc((l+r)/2);
           temp:=rnd(m/n*10);
           if abs(temp-x)<10e-12 then begin
                                     sum:=m;
                                     l:=m+1;
                                     continue;
                                     end;
           if temp<x then l:=m+1
                     else r:=m-1;
           end;
     {writeln(sum:0:0);}
     if sum=-1 then begin
                    writeln('Impossible');
                    exit;
                    end;
     l:=0; r:=2000000000; res:=-1;
     while l<=r do begin
           m:=trunc((l+r)/2);
           temp:=(sum+m)/(n+m);
           if rnd(temp*10)<=y*10 then begin
                                      res:=m;
                                      r:=m-1;
                                      end
                                 else l:=m+1;
           end;
     if res=-1 then writeln('Impossible')
               else writeln(res:0:0);
end.