#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*/ printf(char *, int);
int /*<<< orphan*/ scanf(char *, int *);
int main() {
  int i, j, c, len, num, temp, t, res;
  scanf("%d", &len);
  while (len != 0) {
    printf("%.2f\n", (len / 3.1415926) * (len) / 2);
    scanf("%d", &len);
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeda(%rip),%rdi
lea    -0x14(%rbp),%rsi
call   1040 <scanf@plt>
cmpl   $0x0,-0x14(%rbp)
je     1194 <main+0x74>
cvtsi2sdl -0x14(%rbp),%xmm0
movsd  0xeb2(%rip),%xmm1
divsd  %xmm1,%xmm0
cvtsi2sdl -0x14(%rbp),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xe95(%rip),%xmm1
divsd  %xmm1,%xmm0
cvttsd2si %xmm0,%esi
lea    0xe99(%rip),%rdi
call   1030 <printf@plt>
lea    0xe8a(%rip),%rdi
lea    -0x14(%rbp),%rsi
call   1040 <scanf@plt>
jmp    113f <main+0x1f>
xor    %eax,%eax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %rbx
sub    $0x10,%rsp
lea    0xee0(%rip),%rdi
lea    0xc(%rsp),%rsi
call   1040 <scanf@plt>
mov    0xc(%rsp),%eax
test   %eax,%eax
je     119e <main+0x7e>
lea    0xeca(%rip),%r14
lea    0xec0(%rip),%r15
lea    0xc(%rsp),%rbx
cs nopw 0x0(%rax,%rax,1)
nop
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
movapd %xmm0,%xmm1
divsd  0xe8d(%rip),%xmm1
mulsd  %xmm0,%xmm1
mulsd  0xe89(%rip),%xmm1
cvttsd2si %xmm1,%esi
mov    %r14,%rdi
call   1030 <printf@plt>
mov    %r15,%rdi
mov    %rbx,%rsi
call   1040 <scanf@plt>
mov    0xc(%rsp),%eax
test   %eax,%eax
jne    1160 <main+0x40>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [3 x i8] c"%d\00"
@.str.1 = [6 x i8] c"%.2f\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
%4 = alloca i32
%5 = alloca i32
%6 = alloca i32
%7 = alloca i32
%8 = alloca i32
%9 = alloca i32
store i32 0, i32* %1
%10 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %5)
br label %11
11: ; preds = %14, %0
%12 = load i32, i32* %5
%13 = icmp ne i32 %12, 0
br i1 %13, label %14, label %25
14: ; preds = %11
%15 = load i32, i32* %5
%16 = sitofp i32 %15 to double
%17 = fdiv double %16, 0x400921FB4D12D84A
%18 = load i32, i32* %5
%19 = sitofp i32 %18 to double
%20 = fmul double %17, %19
%21 = fdiv double %20, 2.000000e+00
%22 = fptosi double %21 to i32
%23 = call i32 @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0), i32 %22)
%24 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %5)
br label %11
25: ; preds = %11
ret i32 0
}

LLVM IR (-O2):
@.str = [3 x i8] c"%d\00"
@.str.1 = [6 x i8] c"%.2f\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %1)
%4 = load i32, i32* %1
%5 = icmp eq i32 %4, 0
br i1 %5, label %17, label %6
6: ; preds = %0, %6
%7 = phi i32 [ %15, %6 ], [ %4, %0 ]
%8 = sitofp i32 %7 to double
%9 = fdiv double %8, 0x400921FB4D12D84A
%10 = fmul double %9, %8
%11 = fmul double %10, 5.000000e-01
%12 = fptosi double %11 to i32
%13 = call i32 @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0), i32 %12)
%14 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %1)
%15 = load i32, i32* %1
%16 = icmp eq i32 %15, 0
br i1 %16, label %17, label %6
17: ; preds = %6, %0
ret i32 0
}