var readline=require("readline");
var r2=readline.createInterface({
    input:process.stdin,
    output:process.stdout
});
var arr1 = [];
r2.on("line",function(line){
    arr1.push(line);
   var str=line;
    if(str) {
      var n= howManyTimesPopStr(str);
        console.log(n.join(""));
    }
})
function howManyTimesPopStr(s){  //京东的第二道笔试题
    var str=s;
    var count=0,i=0,j,stack=[],arr=[],sum=1;
    while(i<str.length){
        switch(str[i]){
            case "[":
                stack.push(str[i]);
                arr.push(str[i]);
                count++;
                break;
            case "]":
                    var x=stack[stack.length-1];
                    if(x=='['){
                        stack.pop();
                        arr.push(']');
                    }else{
                        stack.push("]");
                        arr.push(']');
                    }
                break;
        }
        i++;
    }
    while(stack.length>0){
        var x=stack.pop();
        if(x=='['){
            arr.push(']');
        }else{
            arr.unshift('[');
        }
    }
 return arr;
}