$\\$
`S =1 + 2-3-4 + 5 + ... + 2018 - 2019 - 2020 + 2021 + 2022`
`-> S = 1 + (2-3) + (-4+5) + ... + (2018 - 2019) + (-2020 + 2021) + 2022`
`-> S = 1 + (-1) + 1 + ... + (-1) + 1 + 2022`
`->S = 1 + (-1 + 1) + ... + (-1+1) + 2022`
`->S =1 + 0 + ... + 0 + 2022`
`->S=1 + 2022`
`-> S = 2023`
Vậy `S=2023`