{$n+}
program ti;
type data = record
          x,y:extended;
     end;

var ii,jj,n,i:longint;
    fj,xx,fi:extended;
    a:array[-1000..1000]of data;

procedure cl;
var t:longint;
    tt:extended;
begin
     tt:=fi; fi:=fj; fj:=tt;
     t:=ii; ii:=jj; jj:=t;
end;

procedure cl2;
var i:longint;
begin
     if n<ii then begin
        for i:=ii-1 downto n do begin
            a[i].y:=a[i+2].y-a[i+1].y;
            a[i].x:=a[i+2].x-a[i+1].x;
        end;
     end;
     if n>jj then begin
        for i:=jj+1 to n do begin
            a[i].y:=a[i-2].y+a[i-1].y;
            a[i].x:=a[i-2].x+a[i-1].x;
        end;
     end;
     write(a[n].y*fi+a[n].x*xx:0:0);
end;

begin
     for i:=-1000 to 1000 do begin a[i].y:=0; a[i].x:=0; end;
     read(ii,fi,jj,fj,n);
     if n=ii then begin
        write(fi:0:0);
        halt;
     end;
     if n=jj then begin
        write(fj:0:0);
        halt;
     end;
     if ii>jj then cl;
     a[ii].y:=1;
     a[ii].x:=0; a[ii+1].y:=0; a[ii+1].x:=1;
     for i:=ii+2 to jj do begin
         a[i].y:=a[i-1].y+a[i-2].y;
         a[i].x:=a[i-1].x+a[i-2].x;
     end;
     xx:=(fj-a[jj].y*fi)/a[jj].x;
     cl2;
end.