function arrayManipulator(arr1, arr2) {

    for (let i = 0; i < arr2.length; i++) {
        let temp = arr2[i];

        let commands = temp.split(" ");


        let command = commands[0];


        if (command === "add") {
            let index = Number(commands[1]);
            let element = Number(commands[2]);
            let sliced = arr1.slice(0, index);


            arr1 = arr1.slice(index, arr1.length);
            arr1.unshift(element);
            for (let k = sliced.length - 1; k >= 0; k--) {
                let tempK = Number(sliced[k]);

                arr1.unshift(tempK);
                arr1 = arr1;

            }

        } else if (command === "addMany") {
            let indexNum = Number(commands[1]);
            let num = indexNum;
            let sliced = arr1.slice(indexNum, arr1.length);
            let number = Number(arr1.length);
            newArr = arr1.slice(0, indexNum);


            index = 2;
            while (index < commands.length) {
                let temp = Number(commands[index]);

                if (num > arr1.length - 1) {
                    arr1.push(temp);
                    num += 1;

                } else {

                    newArr.push(temp);
                    arr1 = newArr;
                    //indexNum+=1;


                }

                index++
            }

            //arr1.splice(arr1.length, sliced.length, sliced.join(", "))
            if (indexNum < number) {
                for (let k = 0; k < sliced.length; k++) {
                    let tempK = sliced[k];
                    arr1.push(tempK);
                    arr1=arr1;
                }
            }
            //console.log(arr1)

        } else if (command === "contains") {

            let element = Number(commands[1]);

            if (arr1.indexOf(element) != -1) {
                let index = arr1.indexOf(element);
                console.log(index)
            } else {
                console.log(-1)
            }

        } else if (command === "remove") {
            let index = Number(commands[1]);
            arr1.splice(index, 1);
            arr1 = arr1;
            //console.log(arr1);
        } else if (command === "shift") {
            let positions = Number(commands[1]);
            let spliced = arr1.splice(0, positions);
            //arr1 = arr1.reverse();
            for (let i = 0; i < spliced.length; i++) {
                let temp = spliced[i];
                arr1.push(temp);
                arr1 = arr1;
            }
            //console.log(arr1);
        } else if (command === "sumPairs") {
            let newArr = [];
            let sum = 0;
            if (arr1.length % 2 === 0) {
                for (let i = 0; i < arr1.length; i += 2) {
                    let temp1 = Number(arr1[i]);
                    let temp2 = Number(arr1[i + 1]);
                    sum = temp1 + temp2;
                    newArr.push(sum);


                    //console.log(arr1)

                }
                arr1 = newArr;
            }else {
                let last = arr1[arr1.length-1];
                for (let i = 0; i < arr1.length-1; i += 2) {
                    let temp1 = Number(arr1[i]);
                    let temp2 = Number(arr1[i + 1]);
                    sum = temp1 + temp2;
                    newArr.push(sum);

            }

            newArr.push(last);
            arr1 = newArr;
                //console.log(arr1)




        }
    }

        //console.log(arr1.join(', '))

        else if (command === "print") {

            console.log(`[ ${arr1.join(", ")} ]`);
            break;

        }
    }
}