问Ubuntu系统如何安装g++？

我的腾讯云上安装的是Ubuntu系统，系统中没有安装g++

我输入 sudo apt-get install g++

系统显示安装错误

Ign:1 http://mirrors.tencentyun.com/ubuntu focal-security/main amd64 linux-libc-dev amd64 5.4.0-77.86

Err:1 http://mirrors.tencentyun.com/ubuntu focal-security/main amd64 linux-libc-dev amd64 5.4.0-77.86

404 Not Found [IP: 169.254.0.3 80]

E: Failed to fetch http://mirrors.tencentyun.com/ubuntu/pool/main/l/linux/linux-libc-dev_5.4.0-77.86_amd64.deb 404 Not Found [IP: 169.254.0.3 80]

E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

请问有人知道如何解决该问题吗，谢谢了