x86asm-nasm, 662 bytes

Result

WA

Duration

592ms

Code [DL]

section .data
section .text
global _start

write:
push ebp
mov ebp, esp
mov edx, 1
mov ecx, ebp
add ecx, 8
mov ebx, 1
mov eax, 4
int 0x80
leave
ret

pi:
push ebp
mov ebp, esp
mov eax, [ebp+8]
cmp eax, 10
jl NO
mov edx, 0
mov ecx, 10
div ecx
push edx
push eax
call pi
mov eax, [esp+4] ; mod
NO:
add eax, 0x30
push eax
call write
leave
ret

read:
push ebp
mov ebp, esp
push 0
push 0
mov edx, 1
mov ecx, esp
mov ebx, 0
mov eax, 3
int 0x80

mov edx, 1
mov ecx, esp
add ecx, 4
mov ebx, 0
mov eax, 3
int 0x80

mov eax, [esp]
sub eax, 0x30
mov ecx, 10
mul ecx
add eax, [esp+4]
sub eax, 0x30
leave
ret

_start:
push ebp
mov ebp, esp
call read
push eax
call pi
leave
ret

stdin

40 01 06
49 46 98
22 02 62
97 37 42

stdout

40

stderr

Segmentation fault (core dumped)

strace