for(l in readLines("stdin")){j=1
a=c()
for(i in 80:1){s=substr(l,i,i)
if(s=="(")j=j-1
if(length(a)<j)a[j]=paste(rep(" ",i),sep="",collapse="")
substr(a[j],i,i)=s
if(s==")")j=j+1}
write(a,1)}
Note that non-ascii characters in the above source code will be escaped (such as \x9f).