bash-pure, 30 bytes

Result

WA

Code [DL]

read -s -n 1 C
echo $((c+10))

stdin

2412755385946060906166466333439518237787113135368016095076298902897775167614429955633033240338446828

stdout

10

stderr

/bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)

strace