#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 /*<<< orphan*/ quickSort(int *, int /*<<< orphan*/, int);
int /*<<< orphan*/ scanf(char *, int *);
int main() {
  int n;
  int a[1500];
  int i;
  while (1) {
    scanf("%d", &n);
    if (n == 0)
      break;
    for (i = 0; i < n; i++)
      scanf("%d", &a[i]);
    quickSort(a, 0, n - 1);
    int c = 0;
    if (a[n - 1] < 1322) {
      printf("IMPOSSIBLE\n");
      continue;
    }
    for (i = 0; i < n - 1; i++) {
      if (a[i + 1] - a[i] > 200) {
        c++;
        break;
      }
    }
    if (c > 0)
      printf("IMPOSSIBLE\n");
    else
      printf("POSSIBLE\n");
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x1790,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeb7(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1040 <scanf@plt>
cmpl   $0x0,-0x8(%rbp)
jne    1161 <main+0x31>
jmp    129c <main+0x16c>
movl   $0x0,-0x1784(%rbp)
mov    -0x1784(%rbp),%eax
cmp    -0x8(%rbp),%eax
jge    11af <main+0x7f>
movslq -0x1784(%rbp),%rax
lea    -0x1780(%rbp),%rsi
shl    $0x2,%rax
add    %rax,%rsi
lea    0xe6a(%rip),%rdi
call   1040 <scanf@plt>
mov    -0x1784(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x1784(%rbp)
jmp    116b <main+0x3b>
lea    -0x1780(%rbp),%rdi
mov    -0x8(%rbp),%edx
sub    $0x1,%edx
xor    %esi,%esi
call   1050 <quickSort@plt>
movl   $0x0,-0x1788(%rbp)
mov    -0x8(%rbp),%eax
sub    $0x1,%eax
cltq
cmpl   $0x52a,-0x1780(%rbp,%rax,4)
jge    11f7 <main+0xc7>
lea    0xe16(%rip),%rdi
call   1030 <printf@plt>
jmp    1142 <main+0x12>
movl   $0x0,-0x1784(%rbp)
mov    -0x1784(%rbp),%eax
mov    -0x8(%rbp),%ecx
sub    $0x1,%ecx
cmp    %ecx,%eax
jge    126d <main+0x13d>
mov    -0x1784(%rbp),%eax
add    $0x1,%eax
cltq
mov    -0x1780(%rbp,%rax,4),%eax
movslq -0x1784(%rbp),%rcx
sub    -0x1780(%rbp,%rcx,4),%eax
cmp    $0xc8,%eax
jle    1254 <main+0x124>
mov    -0x1788(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x1788(%rbp)
jmp    126d <main+0x13d>
jmp    1259 <main+0x129>
mov    -0x1784(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x1784(%rbp)
jmp    1201 <main+0xd1>
cmpl   $0x0,-0x1788(%rbp)
jle    128b <main+0x15b>
lea    0xd82(%rip),%rdi
call   1030 <printf@plt>
jmp    1297 <main+0x167>
lea    0xd73(%rip),%rdi
call   1030 <printf@plt>
jmp    1142 <main+0x12>
xor    %eax,%eax
add    $0x1790,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
sub    $0x1788,%rsp
lea    0xeb8(%rip),%rdi
lea    0xc(%rsp),%rsi
call   1040 <scanf@plt>
mov    0xc(%rsp),%edx
test   %edx,%edx
je     1225 <main+0xf5>
lea    0x10(%rsp),%r14
lea    0xe96(%rip),%r12
lea    0xe92(%rip),%rbp
lea    0xc(%rsp),%r15
jmp    11a3 <main+0x73>
nopl   0x0(%rax,%rax,1)
lea    0xe7e(%rip),%rdi
call   1030 <puts@plt>
mov    %r12,%rdi
mov    %r15,%rsi
call   1040 <scanf@plt>
mov    0xc(%rsp),%edx
test   %edx,%edx
je     1225 <main+0xf5>
test   %edx,%edx
jle    11cd <main+0x9d>
mov    %r14,%rbx
xor    %r13d,%r13d
nopl   (%rax)
mov    %r12,%rdi
mov    %rbx,%rsi
call   1040 <scanf@plt>
add    $0x1,%r13
movslq 0xc(%rsp),%rdx
add    $0x4,%rbx
cmp    %rdx,%r13
jl     11b0 <main+0x80>
add    $0xffffffff,%edx
mov    %r14,%rdi
xor    %esi,%esi
call   1050 <quickSort@plt>
movslq 0xc(%rsp),%rax
cmpl   $0x52a,0xc(%rsp,%rax,4)
mov    %rbp,%rdi
jl     1187 <main+0x57>
add    $0xffffffffffffffff,%rax
test   %eax,%eax
mov    $0x0,%ecx
cmovle %ecx,%eax
xor    %ecx,%ecx
nopl   0x0(%rax)
cmp    %rcx,%rax
je     1180 <main+0x50>
mov    0x14(%rsp,%rcx,4),%edx
sub    0x10(%rsp,%rcx,4),%edx
add    $0x1,%rcx
cmp    $0xc9,%edx
jl     1200 <main+0xd0>
mov    %rbp,%rdi
jmp    1187 <main+0x57>
xor    %eax,%eax
add    $0x1788,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
@.str = [3 x i8] c"%d\00"
@.str.1 = [12 x i8] c"IMPOSSIBLE\0A\00"
@.str.2 = [10 x i8] c"POSSIBLE\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca [1500 x i32]
%4 = alloca i32
%5 = alloca i32
store i32 0, i32* %1
br label %6
6: ; preds = %0, %35, %69
%7 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %2)
%8 = load i32, i32* %2
%9 = icmp eq i32 %8, 0
br i1 %9, label %10, label %11
10: ; preds = %6
br label %70
11: ; preds = %6
store i32 0, i32* %4
br label %12
12: ; preds = %21, %11
%13 = load i32, i32* %4
%14 = load i32, i32* %2
%15 = icmp slt i32 %13, %14
br i1 %15, label %16, label %24
16: ; preds = %12
%17 = load i32, i32* %4
%18 = sext i32 %17 to i64
%19 = getelementptr inbounds [1500 x i32], [1500 x i32]* %3, i64 0, i64 %18
%20 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %19)
br label %21
21: ; preds = %16
%22 = load i32, i32* %4
%23 = add nsw i32 %22, 1
store i32 %23, i32* %4
br label %12
24: ; preds = %12
%25 = getelementptr inbounds [1500 x i32], [1500 x i32]* %3, i64 0, i64 0
%26 = load i32, i32* %2
%27 = sub nsw i32 %26, 1
%28 = call i32 @quickSort(i32* %25, i32 0, i32 %27)
store i32 0, i32* %5
%29 = load i32, i32* %2
%30 = sub nsw i32 %29, 1
%31 = sext i32 %30 to i64
%32 = getelementptr inbounds [1500 x i32], [1500 x i32]* %3, i64 0, i64 %31
%33 = load i32, i32* %32
%34 = icmp slt i32 %33, 1322
br i1 %34, label %35, label %37
35: ; preds = %24
%36 = call i32 @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.1, i64 0, i64 0))
br label %6
37: ; preds = %24
store i32 0, i32* %4
br label %38
38: ; preds = %59, %37
%39 = load i32, i32* %4
%40 = load i32, i32* %2
%41 = sub nsw i32 %40, 1
%42 = icmp slt i32 %39, %41
br i1 %42, label %43, label %62
43: ; preds = %38
%44 = load i32, i32* %4
%45 = add nsw i32 %44, 1
%46 = sext i32 %45 to i64
%47 = getelementptr inbounds [1500 x i32], [1500 x i32]* %3, i64 0, i64 %46
%48 = load i32, i32* %47
%49 = load i32, i32* %4
%50 = sext i32 %49 to i64
%51 = getelementptr inbounds [1500 x i32], [1500 x i32]* %3, i64 0, i64 %50
%52 = load i32, i32* %51
%53 = sub nsw i32 %48, %52
%54 = icmp sgt i32 %53, 200
br i1 %54, label %55, label %58
55: ; preds = %43
%56 = load i32, i32* %5
%57 = add nsw i32 %56, 1
store i32 %57, i32* %5
br label %62
58: ; preds = %43
br label %59
59: ; preds = %58
%60 = load i32, i32* %4
%61 = add nsw i32 %60, 1
store i32 %61, i32* %4
br label %38
62: ; preds = %55, %38
%63 = load i32, i32* %5
%64 = icmp sgt i32 %63, 0
br i1 %64, label %65, label %67
65: ; preds = %62
%66 = call i32 @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.1, i64 0, i64 0))
br label %69
67: ; preds = %62
%68 = call i32 @printf(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.2, i64 0, i64 0))
br label %69
69: ; preds = %67, %65
br label %6
70: ; preds = %10
ret i32 0
}

LLVM IR (-O2):
@.str = [3 x i8] c"%d\00"
@str = [9 x i8] c"POSSIBLE\00"
@str.4 = [11 x i8] c"IMPOSSIBLE\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca [1500 x i32]
%3 = bitcast i32* %1 to i8*
%4 = bitcast [1500 x i32]* %2 to i8*
%5 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %1)
%6 = load i32, i32* %1
%7 = icmp eq i32 %6, 0
br i1 %7, label %51, label %8
8: ; preds = %0
%9 = getelementptr inbounds [1500 x i32], [1500 x i32]* %2, i64 0, i64 0
br label %10
10: ; preds = %8, %45
%11 = phi i32 [ %6, %8 ], [ %49, %45 ]
%12 = icmp sgt i32 %11, 0
br i1 %12, label %13, label %21
13: ; preds = %10, %13
%14 = phi i64 [ %17, %13 ], [ 0, %10 ]
%15 = getelementptr inbounds [1500 x i32], [1500 x i32]* %2, i64 0, i64 %14
%16 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %15)
%17 = add nuw nsw i64 %14, 1
%18 = load i32, i32* %1
%19 = sext i32 %18 to i64
%20 = icmp slt i64 %17, %19
br i1 %20, label %13, label %21
21: ; preds = %13, %10
%22 = phi i32 [ %11, %10 ], [ %18, %13 ]
%23 = add nsw i32 %22, -1
%24 = call i32 @quickSort(i32* %9, i32 0, i32 %23)
%25 = load i32, i32* %1
%26 = add nsw i32 %25, -1
%27 = sext i32 %26 to i64
%28 = getelementptr inbounds [1500 x i32], [1500 x i32]* %2, i64 0, i64 %27
%29 = load i32, i32* %28
%30 = icmp slt i32 %29, 1322
br i1 %30, label %45, label %31
31: ; preds = %21
%32 = call i32 @llvm.smax.i32(i32 %26, i32 0)
%33 = zext i32 %32 to i64
br label %34
34: ; preds = %31, %37
%35 = phi i64 [ 0, %31 ], [ %38, %37 ]
%36 = icmp eq i64 %35, %33
br i1 %36, label %45, label %37
37: ; preds = %34
%38 = add nuw nsw i64 %35, 1
%39 = getelementptr inbounds [1500 x i32], [1500 x i32]* %2, i64 0, i64 %38
%40 = load i32, i32* %39
%41 = getelementptr inbounds [1500 x i32], [1500 x i32]* %2, i64 0, i64 %35
%42 = load i32, i32* %41
%43 = sub nsw i32 %40, %42
%44 = icmp sgt i32 %43, 200
br i1 %44, label %45, label %34
45: ; preds = %34, %37, %21
%46 = phi i8* [ getelementptr inbounds ([11 x i8], [11 x i8]* @str.4, i64 0, i64 0), %21 ], [ getelementptr inbounds ([11 x i8], [11 x i8]* @str.4, i64 0, i64 0), %37 ], [ getelementptr inbounds ([9 x i8], [9 x i8]* @str, i64 0, i64 0), %34 ]
%47 = call i32 @puts(i8* dereferenceable(1) %46)
%48 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %1)
%49 = load i32, i32* %1
%50 = icmp eq i32 %49, 0
br i1 %50, label %51, label %10
51: ; preds = %45, %0
ret i32 0
}