eval {2,5}'
e+=m%$_==0?m/=$_,n=10/$_*n%10:
n=$m
read m
m=${m%${m/*[^0]}}
'
'a?a=b%(b=a),_:b'
for((a=n,b=m,n=n/_%10,m/=_;$e 0;)){ :;}
echo $[m-1?-1:n]