; LLVM IR from tangjz/acm-icpc :: codeforces/complete (526B)

; Unoptimized IR (clang -disable-llvm-passes):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl" }
%"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl" = type { %"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl_data" }
%"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl_data" = type { ptr, ptr, ptr }
%"struct.std::pair" = type { i32, i32 }

@n = external dso_local global i32, align 4
@ans = external dso_local global i64, align 8
@g = external dso_local global [500001 x %"class.std::vector"], align 16
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [7 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsii(i32 noundef, i32 noundef) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #2 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca %"struct.std::pair", align 4
  %5 = alloca i32, align 4
  %6 = alloca %"struct.std::pair", align 4
  store i32 0, ptr %1, align 4
  %7 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef @n)
  %8 = load i32, ptr @n, align 4, !tbaa !5
  %9 = add nsw i32 %8, 1
  %10 = shl i32 1, %9
  %11 = sub nsw i32 %10, 1
  store i32 %11, ptr @n, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #4
  store i32 2, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  br label %12

12:                                               ; preds = %30, %0
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = load i32, ptr @n, align 4, !tbaa !5
  %15 = icmp sle i32 %13, %14
  br i1 %15, label %17, label %16

16:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #4
  br label %33

17:                                               ; preds = %12
  %18 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %3)
  %19 = load i32, ptr %2, align 4, !tbaa !5
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds [500001 x %"class.std::vector"], ptr @g, i64 0, i64 %20
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  %22 = load i32, ptr %2, align 4, !tbaa !5
  %23 = ashr i32 %22, 1
  store i32 %23, ptr %5, align 4, !tbaa !5
  %24 = call i64 @_ZSt9make_pairIiRiESt4pairINSt25__strip_reference_wrapperINSt5decayIT_E4typeEE6__typeENS2_INS3_IT0_E4typeEE6__typeEEOS4_OS9_(ptr noundef nonnull align 4 dereferenceable(4) %5, ptr noundef nonnull align 4 dereferenceable(4) %3)
  store i64 %24, ptr %4, align 4
  call void @_ZNSt6vectorISt4pairIiiESaIS1_EE9push_backEOS1_(ptr noundef nonnull align 8 dereferenceable(24) %21, ptr noundef nonnull align 4 dereferenceable(8) %4)
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #4
  %25 = load i32, ptr %2, align 4, !tbaa !5
  %26 = ashr i32 %25, 1
  %27 = sext i32 %26 to i64
  %28 = getelementptr inbounds [500001 x %"class.std::vector"], ptr @g, i64 0, i64 %27
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #4
  %29 = call i64 @_ZSt9make_pairIRiS0_ESt4pairINSt25__strip_reference_wrapperINSt5decayIT_E4typeEE6__typeENS2_INS3_IT0_E4typeEE6__typeEEOS4_OS9_(ptr noundef nonnull align 4 dereferenceable(4) %2, ptr noundef nonnull align 4 dereferenceable(4) %3)
  store i64 %29, ptr %6, align 4
  call void @_ZNSt6vectorISt4pairIiiESaIS1_EE9push_backEOS1_(ptr noundef nonnull align 8 dereferenceable(24) %28, ptr noundef nonnull align 4 dereferenceable(8) %6)
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #4
  br label %30

30:                                               ; preds = %17
  %31 = load i32, ptr %2, align 4, !tbaa !5
  %32 = add nsw i32 %31, 1
  store i32 %32, ptr %2, align 4, !tbaa !5
  br label %12, !llvm.loop !9

33:                                               ; preds = %16
  call void @_Z3dfsii(i32 noundef 1, i32 noundef 0)
  %34 = load i64, ptr @ans, align 8, !tbaa !11
  %35 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i64 noundef %34)
  ret i32 0
}

declare i32 @__isoc99_scanf(ptr noundef, ...) #3

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorISt4pairIiiESaIS1_EE9push_backEOS1_(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(8)) #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local i64 @_ZSt9make_pairIiRiESt4pairINSt25__strip_reference_wrapperINSt5decayIT_E4typeEE6__typeENS2_INS3_IT0_E4typeEE6__typeEEOS4_OS9_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #0

; Function Attrs: mustprogress uwtable
declare dso_local i64 @_ZSt9make_pairIRiS0_ESt4pairINSt25__strip_reference_wrapperINSt5decayIT_E4typeEE6__typeENS2_INS3_IT0_E4typeEE6__typeEEOS4_OS9_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #0

declare i32 @printf(ptr noundef, ...) #3

attributes #0 = { mustprogress uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { mustprogress norecurse uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #3 = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #4 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!12, !12, i64 0}
!12 = !{!"long long", !7, i64 0}


; Optimized IR (opt -passes='default<O3>'):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl" }
%"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl" = type { %"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl_data" }
%"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl_data" = type { ptr, ptr, ptr }
%"struct.std::pair" = type { i32, i32 }

@n = external dso_local global i32, align 4
@ans = external dso_local local_unnamed_addr global i64, align 8
@g = external dso_local global [500001 x %"class.std::vector"], align 16
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [7 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsii(i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca %"struct.std::pair", align 8
  %4 = alloca i32, align 4
  %5 = alloca %"struct.std::pair", align 8
  %6 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull @n)
  %7 = load i32, ptr @n, align 4, !tbaa !5
  %8 = add nsw i32 %7, 1
  %notmask = shl nsw i32 -1, %8
  %9 = xor i32 %notmask, -1
  store i32 %9, ptr @n, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  store i32 2, ptr %1, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #4
  %.not1 = icmp ugt i32 %notmask, -3
  br i1 %.not1, label %._crit_edge, label %.lr.ph

._crit_edge:                                      ; preds = %.lr.ph, %0
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #4
  call void @_Z3dfsii(i32 noundef 1, i32 noundef 0)
  %10 = load i64, ptr @ans, align 8, !tbaa !9
  %11 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i64 noundef %10)
  ret i32 0

.lr.ph:                                           ; preds = %0, %.lr.ph
  %12 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %2)
  %13 = load i32, ptr %1, align 4, !tbaa !5
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds [500001 x %"class.std::vector"], ptr @g, i64 0, i64 %14
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %3) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %4) #4
  %16 = ashr i32 %13, 1
  store i32 %16, ptr %4, align 4, !tbaa !5
  %17 = call i64 @_ZSt9make_pairIiRiESt4pairINSt25__strip_reference_wrapperINSt5decayIT_E4typeEE6__typeENS2_INS3_IT0_E4typeEE6__typeEEOS4_OS9_(ptr noundef nonnull align 4 dereferenceable(4) %4, ptr noundef nonnull align 4 dereferenceable(4) %2)
  store i64 %17, ptr %3, align 8
  call void @_ZNSt6vectorISt4pairIiiESaIS1_EE9push_backEOS1_(ptr noundef nonnull align 8 dereferenceable(24) %15, ptr noundef nonnull align 4 dereferenceable(8) %3)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %4) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #4
  %18 = load i32, ptr %1, align 4, !tbaa !5
  %19 = ashr i32 %18, 1
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds [500001 x %"class.std::vector"], ptr @g, i64 0, i64 %20
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %5) #4
  %22 = call i64 @_ZSt9make_pairIRiS0_ESt4pairINSt25__strip_reference_wrapperINSt5decayIT_E4typeEE6__typeENS2_INS3_IT0_E4typeEE6__typeEEOS4_OS9_(ptr noundef nonnull align 4 dereferenceable(4) %1, ptr noundef nonnull align 4 dereferenceable(4) %2)
  store i64 %22, ptr %5, align 8
  call void @_ZNSt6vectorISt4pairIiiESaIS1_EE9push_backEOS1_(ptr noundef nonnull align 8 dereferenceable(24) %21, ptr noundef nonnull align 4 dereferenceable(8) %5)
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %5) #4
  %23 = load i32, ptr %1, align 4, !tbaa !5
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %1, align 4, !tbaa !5
  %25 = load i32, ptr @n, align 4, !tbaa !5
  %.not.not = icmp slt i32 %23, %25
  br i1 %.not.not, label %.lr.ph, label %._crit_edge, !llvm.loop !11
}

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #3

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorISt4pairIiiESaIS1_EE9push_backEOS1_(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(8)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local i64 @_ZSt9make_pairIiRiESt4pairINSt25__strip_reference_wrapperINSt5decayIT_E4typeEE6__typeENS2_INS3_IT0_E4typeEE6__typeEEOS4_OS9_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
declare dso_local i64 @_ZSt9make_pairIRiS0_ESt4pairINSt25__strip_reference_wrapperINSt5decayIT_E4typeEE6__typeENS2_INS3_IT0_E4typeEE6__typeEEOS4_OS9_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #0

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #3

attributes #0 = { mustprogress uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { mustprogress norecurse uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #3 = { nofree nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #4 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"long long", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GlobalOptPass,IPSCCPPass,InferAlignmentPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass