#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 */
scalar_t__ EOF;
scalar_t__ pow(int, int);
int /*<<< orphan*/ printf(char *, long long);
scalar_t__ scanf(char *, int *);
int main() {
  int n;
  long long result;
  while (scanf("%d", &n) != EOF) {
    result = (long long)pow(2, n - 1);
    printf("%ld\n", result);
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeba(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1040 <scanf@plt>
mov    0x2e92(%rip),%rcx
cmp    (%rcx),%rax
je     1188 <main+0x58>
mov    -0x8(%rbp),%esi
sub    $0x1,%esi
mov    $0x2,%edi
call   1050 <pow@plt>
mov    %rax,-0x10(%rbp)
mov    -0x10(%rbp),%rsi
lea    0xe85(%rip),%rdi
call   1030 <printf@plt>
jmp    113f <main+0xf>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
lea    0xec1(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1040 <scanf@plt>
mov    0x2e98(%rip),%r12
cmp    (%r12),%rax
je     119d <main+0x6d>
lea    0xea6(%rip),%r14
lea    0xe9c(%rip),%r15
lea    0x4(%rsp),%rbx
nopl   0x0(%rax)
mov    0x4(%rsp),%esi
add    $0xffffffff,%esi
mov    $0x2,%edi
call   1050 <pow@plt>
mov    %r14,%rdi
mov    %rax,%rsi
call   1030 <printf@plt>
mov    %r15,%rdi
mov    %rbx,%rsi
call   1040 <scanf@plt>
cmp    (%r12),%rax
jne    1170 <main+0x40>
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret

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

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