e="%c%%c" c=e==e cc=c+c+c+c x=cc+cc cx=x+x+x+x ce=cx+cx ee=cx+x+cc ex=ce+ee xc=ex+c+c xe=xc+c xx=xc+cc cc+=cx+ce ce+=x x+=xe x=""""%ce%%c"""%ce%ex+e%ex%xe+e%ee%cx+e%x%xe+e%xx%ex xe+=c c+=cx ee+=ce ce+=c exec""+e%xe%xx+e%ce%xc+"%c"%ee+x+e%cc%c+"""" """
Note that non-ascii characters in the above source code will be escaped (such as \x9f).