var f =function(s,i,x){for(s=s.split("");(i=s.shift())&&s[0];)with(s)eval({";":"s=concat(slice(-1))",":":"s=concat(pop().split(''))",".":"pop()","/":"push(pop(),pop())",".":"push(pop()+pop())","|":"reverse()","[":"for(i=-(x=1);x&&s[++i];)x+={'[':1,']':-1}[s[i]]||0;push(splice(0,i).join(''))"}[i]);return i}