SOURCE

function allSubsets(arr){
let res = [[]];
for(let i = 0; i < arr.length; i++){
const tempRes = res.map(subset => {
const one = subset.concat([]);
one.push(arr[i]);
return one;
})
res = res.concat(tempRes);
}
return res;
}
var line;
while(line = read_line()){
let splitLine = line.split(' ')
print(JSON.stringify(allSubsets(splitLine.map(Number))))
}