File standardInput readLines map(split map(asNumber)do(f:=0
while(f<1,join(" ")println
if(at(0)+at(3)>0,push(at(0));for(i,0,3,atPut(i,(at(i)-at(i+1))abs))
pop,f=1))writeln))
Note that non-ascii characters in the above source code will be escaped (such as \x9f).