#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 scanf(char *, double *, double *, double *, double *);
int main() {
  double x1, y1, x2, y2;
  double ox, oy;
  while (scanf("%lf%lf%lf%lf", &x1, &y1, &x2, &y2) == 4) {
    if (x1 == x2 && y1 == y2) {
      printf("Impossible.\n");
      continue;
    }
    ox = (x1 + x2) / 2.0;
    oy = (y1 + y2) / 2.0;
    x1 -= ox, y1 -= oy;
    x2 -= ox, y2 -= oy;
    printf("%lf %lf %lf %lf\n", -y1 + ox, x1 + oy, -y2 + ox, x2 + oy);
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x40,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xed2(%rip),%rdi
lea    -0x10(%rbp),%rsi
lea    -0x18(%rbp),%rdx
lea    -0x20(%rbp),%rcx
lea    -0x28(%rbp),%r8
call   1040 <scanf@plt>
cmp    $0x4,%eax
jne    127e <main+0x15e>
movsd  -0x10(%rbp),%xmm0
ucomisd -0x20(%rbp),%xmm0
jne    1193 <main+0x73>
jp     1193 <main+0x73>
movsd  -0x18(%rbp),%xmm0
ucomisd -0x28(%rbp),%xmm0
jne    1193 <main+0x73>
jp     1193 <main+0x73>
lea    0xe8e(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
jmp    112f <main+0xf>
movsd  -0x10(%rbp),%xmm0
addsd  -0x20(%rbp),%xmm0
movsd  0xe5b(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x30(%rbp)
movsd  -0x18(%rbp),%xmm0
addsd  -0x28(%rbp),%xmm0
movsd  0xe40(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x38(%rbp)
movsd  -0x30(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x10(%rbp)
movsd  -0x38(%rbp),%xmm1
movsd  -0x18(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  -0x30(%rbp),%xmm1
movsd  -0x20(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x20(%rbp)
movsd  -0x38(%rbp),%xmm1
movsd  -0x28(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x28(%rbp)
movsd  -0x18(%rbp),%xmm0
movq   %xmm0,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm0
addsd  -0x30(%rbp),%xmm0
movsd  -0x10(%rbp),%xmm1
addsd  -0x38(%rbp),%xmm1
movsd  -0x28(%rbp),%xmm2
movq   %xmm2,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm2
addsd  -0x30(%rbp),%xmm2
movsd  -0x20(%rbp),%xmm3
addsd  -0x38(%rbp),%xmm3
lea    0xdb0(%rip),%rdi
mov    $0x4,%al
call   1030 <printf@plt>
jmp    112f <main+0xf>
xor    %eax,%eax
add    $0x40,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
sub    $0x28,%rsp
lea    0xec3(%rip),%rdi
lea    0x20(%rsp),%rsi
lea    0x18(%rsp),%rdx
lea    0x10(%rsp),%rcx
lea    0x8(%rsp),%r8
call   1050 <scanf@plt>
cmp    $0x4,%eax
jne    1255 <main+0x125>
lea    0xe9a(%rip),%r15
lea    0x20(%rsp),%r12
lea    0x18(%rsp),%r13
lea    0x10(%rsp),%rbx
lea    0x8(%rsp),%rbp
lea    0xe8c(%rip),%r14
jmp    120f <main+0xdf>
xchg   %ax,%ax
movapd %xmm1,%xmm2
addsd  %xmm3,%xmm2
movsd  0xe60(%rip),%xmm0
mulsd  %xmm0,%xmm2
movapd %xmm5,%xmm6
addsd  %xmm4,%xmm6
mulsd  %xmm0,%xmm6
subsd  %xmm2,%xmm1
movsd  %xmm1,0x20(%rsp)
subsd  %xmm6,%xmm5
movsd  %xmm5,0x18(%rsp)
subsd  %xmm2,%xmm3
movsd  %xmm3,0x10(%rsp)
subsd  %xmm6,%xmm4
movsd  %xmm4,0x8(%rsp)
movapd %xmm2,%xmm0
subsd  %xmm5,%xmm0
addsd  %xmm6,%xmm1
subsd  %xmm4,%xmm2
addsd  %xmm6,%xmm3
mov    %r14,%rdi
mov    $0x4,%al
call   1040 <printf@plt>
mov    %r15,%rdi
mov    %r12,%rsi
mov    %r13,%rdx
mov    %rbx,%rcx
mov    %rbp,%r8
call   1050 <scanf@plt>
cmp    $0x4,%eax
jne    1255 <main+0x125>
movsd  0x20(%rsp),%xmm1
movsd  0x10(%rsp),%xmm3
ucomisd %xmm3,%xmm1
movsd  0x18(%rsp),%xmm5
movsd  0x8(%rsp),%xmm4
jne    1190 <main+0x60>
jp     1190 <main+0x60>
ucomisd %xmm4,%xmm5
jne    1190 <main+0x60>
jp     1190 <main+0x60>
lea    0xdd8(%rip),%rdi
call   1030 <puts@plt>
jmp    11f6 <main+0xc6>
xor    %eax,%eax
add    $0x28,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
@.str = [13 x i8] c"%lf%lf%lf%lf\00"
@.str.1 = [13 x i8] c"Impossible.\0A\00"
@.str.2 = [17 x i8] c"%lf %lf %lf %lf\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca double
%3 = alloca double
%4 = alloca double
%5 = alloca double
%6 = alloca double
%7 = alloca double
store i32 0, i32* %1
br label %8
8: ; preds = %21, %19, %0
%9 = call i32 @scanf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i64 0, i64 0), double* %2, double* %3, double* %4, double* %5)
%10 = icmp eq i32 %9, 4
br i1 %10, label %11, label %57
11: ; preds = %8
%12 = load double, double* %2
%13 = load double, double* %4
%14 = fcmp oeq double %12, %13
br i1 %14, label %15, label %21
15: ; preds = %11
%16 = load double, double* %3
%17 = load double, double* %5
%18 = fcmp oeq double %16, %17
br i1 %18, label %19, label %21
19: ; preds = %15
%20 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.1, i64 0, i64 0))
br label %8
21: ; preds = %15, %11
%22 = load double, double* %2
%23 = load double, double* %4
%24 = fadd double %22, %23
%25 = fdiv double %24, 2.000000e+00
store double %25, double* %6
%26 = load double, double* %3
%27 = load double, double* %5
%28 = fadd double %26, %27
%29 = fdiv double %28, 2.000000e+00
store double %29, double* %7
%30 = load double, double* %6
%31 = load double, double* %2
%32 = fsub double %31, %30
store double %32, double* %2
%33 = load double, double* %7
%34 = load double, double* %3
%35 = fsub double %34, %33
store double %35, double* %3
%36 = load double, double* %6
%37 = load double, double* %4
%38 = fsub double %37, %36
store double %38, double* %4
%39 = load double, double* %7
%40 = load double, double* %5
%41 = fsub double %40, %39
store double %41, double* %5
%42 = load double, double* %3
%43 = fneg double %42
%44 = load double, double* %6
%45 = fadd double %43, %44
%46 = load double, double* %2
%47 = load double, double* %7
%48 = fadd double %46, %47
%49 = load double, double* %5
%50 = fneg double %49
%51 = load double, double* %6
%52 = fadd double %50, %51
%53 = load double, double* %4
%54 = load double, double* %7
%55 = fadd double %53, %54
%56 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str.2, i64 0, i64 0), double %45, double %48, double %52, double %55)
br label %8
57: ; preds = %8
ret i32 0
}

LLVM IR (-O2):
@.str = [13 x i8] c"%lf%lf%lf%lf\00"
@.str.2 = [17 x i8] c"%lf %lf %lf %lf\0A\00"
@str = [12 x i8] c"Impossible.\00"
define i32 @main() {
%1 = alloca double
%2 = alloca double
%3 = alloca double
%4 = alloca double
%5 = bitcast double* %1 to i8*
%6 = bitcast double* %2 to i8*
%7 = bitcast double* %3 to i8*
%8 = bitcast double* %4 to i8*
%9 = call i32 @scanf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i64 0, i64 0), double* %1, double* %2, double* %3, double* %4)
%10 = icmp eq i32 %9, 4
br i1 %10, label %11, label %38
11: ; preds = %0, %21
%12 = load double, double* %1
%13 = load double, double* %3
%14 = fcmp oeq double %12, %13
%15 = load double, double* %2
%16 = load double, double* %4
%17 = fcmp oeq double %15, %16
%18 = select i1 %14, i1 %17, i1 false
br i1 %18, label %19, label %24
19: ; preds = %11
%20 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([12 x i8], [12 x i8]* @str, i64 0, i64 0))
br label %21
21: ; preds = %19, %24
%22 = call i32 @scanf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i64 0, i64 0), double* %1, double* %2, double* %3, double* %4)
%23 = icmp eq i32 %22, 4
br i1 %23, label %11, label %38
24: ; preds = %11
%25 = fadd double %12, %13
%26 = fmul double %25, 5.000000e-01
%27 = fadd double %15, %16
%28 = fmul double %27, 5.000000e-01
%29 = fsub double %12, %26
store double %29, double* %1
%30 = fsub double %15, %28
store double %30, double* %2
%31 = fsub double %13, %26
store double %31, double* %3
%32 = fsub double %16, %28
store double %32, double* %4
%33 = fsub double %26, %30
%34 = fadd double %29, %28
%35 = fsub double %26, %32
%36 = fadd double %31, %28
%37 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([17 x i8], [17 x i8]* @.str.2, i64 0, i64 0), double %33, double %34, double %35, double %36)
br label %21
38: ; preds = %21, %0
ret i32 0
}