List of best mirrors for IP address 2600:1f28:365:80b0:97f7:bcae:b24c:a081, located in United States (US).
I am very sorry, but no mirror was found. Feel free to download directly:
http://raspbian.raspberrypi.org/raspbian/pool/main/libs/libstdc++-arm-none-eabi/libstdc++-aarch64-none-elf_15.3.rel1-1+33_all.deb