#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
int /*<<< orphan*/ modexpo(long long, long long, int);
int /*<<< orphan*/ printf(char *, int /*<<< orphan*/);
int /*<<< orphan*/ scanf(char *, ...);
int main() {
  int t;
  scanf("%d", &t);
  while (t--) {
    long long a, b;
    scanf("%lld%lld", &a, &b);
    printf("%lld\n", modexpo(a, b, 10));
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeba(%rip),%rdi
lea    -0x8(%rbp),%rsi
mov    $0x0,%al
call   1050 <scanf@plt>
mov    -0x8(%rbp),%eax
mov    %eax,%ecx
add    $0xffffffff,%ecx
mov    %ecx,-0x8(%rbp)
cmp    $0x0,%eax
je     11a0 <main+0x70>
lea    0xe97(%rip),%rdi
lea    -0x10(%rbp),%rsi
lea    -0x18(%rbp),%rdx
mov    $0x0,%al
call   1050 <scanf@plt>
mov    -0x10(%rbp),%rdi
mov    -0x18(%rbp),%rsi
mov    $0xa,%edx
call   1030 <modexpo@plt>
mov    %eax,%esi
lea    0xe76(%rip),%rdi
call   1040 <printf@plt>
jmp    1151 <main+0x21>
xor    %eax,%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %r12
push   %rbx
sub    $0x18,%rsp
lea    0xebe(%rip),%rdi
lea    0x4(%rsp),%rsi
xor    %eax,%eax
call   1050 <scanf@plt>
subl   $0x1,0x4(%rsp)
jb     11a5 <main+0x75>
lea    0xea7(%rip),%r14
lea    0x10(%rsp),%r15
lea    0x8(%rsp),%r12
lea    0xe9f(%rip),%rbx
nopl   (%rax)
mov    %r14,%rdi
mov    %r15,%rsi
mov    %r12,%rdx
xor    %eax,%eax
call   1050 <scanf@plt>
mov    0x10(%rsp),%rdi
mov    0x8(%rsp),%rsi
mov    $0xa,%edx
call   1030 <modexpo@plt>
mov    %rbx,%rdi
mov    %eax,%esi
call   1040 <printf@plt>
subl   $0x1,0x4(%rsp)
jae    1170 <main+0x40>
xor    %eax,%eax
add    $0x18,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [3 x i8] c"%d\00"
@.str.1 = [9 x i8] c"%lld%lld\00"
@.str.2 = [6 x i8] c"%lld\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i64
%4 = alloca i64
store i32 0, i32* %1
%5 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %2)
br label %6
6: ; preds = %10, %0
%7 = load i32, i32* %2
%8 = add nsw i32 %7, -1
store i32 %8, i32* %2
%9 = icmp ne i32 %7, 0
br i1 %9, label %10, label %16
10: ; preds = %6
%11 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.1, i64 0, i64 0), i64* %3, i64* %4)
%12 = load i64, i64* %3
%13 = load i64, i64* %4
%14 = call i32 @modexpo(i64 %12, i64 %13, i32 10)
%15 = call i32 @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.2, i64 0, i64 0), i32 %14)
br label %6
16: ; preds = %6
ret i32 0
}

LLVM IR (-O2):
@.str = [3 x i8] c"%d\00"
@.str.1 = [9 x i8] c"%lld%lld\00"
@.str.2 = [6 x i8] c"%lld\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i64
%3 = alloca i64
%4 = bitcast i32* %1 to i8*
%5 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %1)
%6 = load i32, i32* %1
%7 = add nsw i32 %6, -1
store i32 %7, i32* %1
%8 = icmp eq i32 %6, 0
br i1 %8, label %21, label %9
9: ; preds = %0
%10 = bitcast i64* %2 to i8*
%11 = bitcast i64* %3 to i8*
br label %12
12: ; preds = %9, %12
%13 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.1, i64 0, i64 0), i64* %2, i64* %3)
%14 = load i64, i64* %2
%15 = load i64, i64* %3
%16 = call i32 @modexpo(i64 %14, i64 %15, i32 10)
%17 = call i32 @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.2, i64 0, i64 0), i32 %16)
%18 = load i32, i32* %1
%19 = add nsw i32 %18, -1
store i32 %19, i32* %1
%20 = icmp eq i32 %18, 0
br i1 %20, label %21, label %12
21: ; preds = %12, %0
ret i32 0
}