; LLVM IR from DionysiosB/CodeForces :: 1500-1599 (1549A-GregorAndCryptography)

; 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"

@.str = external hidden unnamed_addr constant [4 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [9 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #3
  %4 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %2)
  br label %5

5:                                                ; preds = %9, %0
  %6 = load i64, ptr %2, align 8, !tbaa !5
  %7 = add nsw i64 %6, -1
  store i64 %7, ptr %2, align 8, !tbaa !5
  %8 = icmp ne i64 %6, 0
  br i1 %8, label %9, label %17

9:                                                ; preds = %5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  %10 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %3)
  %11 = load i64, ptr %3, align 8, !tbaa !5
  %12 = sub nsw i64 %11, 1
  %13 = sdiv i64 %12, 2
  %14 = load i64, ptr %3, align 8, !tbaa !5
  %15 = sub nsw i64 %14, 1
  %16 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i64 noundef %13, i64 noundef %15)
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  br label %5, !llvm.loop !9

17:                                               ; preds = %5
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #3
  %18 = load i32, ptr %1, align 4
  ret i32 %18
}

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

declare i32 @__isoc99_scanf(ptr noundef, ...) #2

declare i32 @printf(ptr noundef, ...) #2

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

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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 = { 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 = !{!"long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; 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"

@.str = external hidden unnamed_addr constant [4 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [9 x i8], align 1

; Function Attrs: mustprogress nofree norecurse nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i64, align 8
  %2 = alloca i64, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %1) #3
  %3 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %1)
  %4 = load i64, ptr %1, align 8, !tbaa !5
  %5 = add nsw i64 %4, -1
  store i64 %5, ptr %1, align 8, !tbaa !5
  %.not1 = icmp eq i64 %4, 0
  br i1 %.not1, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %.lr.ph
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #3
  %6 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %2)
  %7 = load i64, ptr %2, align 8, !tbaa !5
  %8 = add nsw i64 %7, -1
  %9 = sdiv i64 %8, 2
  %10 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i64 noundef %9, i64 noundef %8)
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #3
  %11 = load i64, ptr %1, align 8, !tbaa !5
  %12 = add nsw i64 %11, -1
  store i64 %12, ptr %1, align 8, !tbaa !5
  %.not = icmp eq i64 %11, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %0
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %1) #3
  ret i32 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: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

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

attributes #0 = { mustprogress nofree norecurse nounwind 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 = { 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 #3 = { 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 = !{!"long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass