; LLVM IR from tangjz/acm-icpc :: 51nod (1353)

; 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"

%struct.Edge = type { i32, i32 }

@n = external dso_local global i32, align 4
@k = external dso_local global i32, align 4
@tot = external dso_local global i32, align 4
@pre = external dso_local global [2002 x i32], align 16
@g = external dso_local global [2002 x [2002 x i32]], align 16
@e = external dso_local global [4004 x %struct.Edge], align 16
@.str = external hidden unnamed_addr constant [5 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [4 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: nocallback nofree nounwind willreturn memory(argmem: readwrite)
declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) #2

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

8:                                                ; preds = %45, %0
  %9 = load i32, ptr %2, align 4, !tbaa !5
  %10 = load i32, ptr @n, align 4, !tbaa !5
  %11 = icmp slt i32 %9, %10
  br i1 %11, label %13, label %12

12:                                               ; preds = %8
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #5
  br label %48

13:                                               ; preds = %8
  %14 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %3, ptr noundef %4)
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #5
  %15 = getelementptr inbounds %struct.Edge, ptr %5, i32 0, i32 0
  %16 = load i32, ptr %3, align 4, !tbaa !5
  %17 = sext i32 %16 to i64
  %18 = getelementptr inbounds [2002 x i32], ptr @pre, i64 0, i64 %17
  %19 = load i32, ptr %18, align 4, !tbaa !5
  store i32 %19, ptr %15, align 4, !tbaa !9
  %20 = getelementptr inbounds %struct.Edge, ptr %5, i32 0, i32 1
  %21 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %21, ptr %20, align 4, !tbaa !11
  %22 = load i32, ptr @tot, align 4, !tbaa !5
  %23 = add nsw i32 %22, 1
  store i32 %23, ptr @tot, align 4, !tbaa !5
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds [4004 x %struct.Edge], ptr @e, i64 0, i64 %24
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %25, ptr align 4 %5, i64 8, i1 false), !tbaa.struct !12
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #5
  %26 = load i32, ptr @tot, align 4, !tbaa !5
  %27 = load i32, ptr %3, align 4, !tbaa !5
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds [2002 x i32], ptr @pre, i64 0, i64 %28
  store i32 %26, ptr %29, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #5
  %30 = getelementptr inbounds %struct.Edge, ptr %6, i32 0, i32 0
  %31 = load i32, ptr %4, align 4, !tbaa !5
  %32 = sext i32 %31 to i64
  %33 = getelementptr inbounds [2002 x i32], ptr @pre, i64 0, i64 %32
  %34 = load i32, ptr %33, align 4, !tbaa !5
  store i32 %34, ptr %30, align 4, !tbaa !9
  %35 = getelementptr inbounds %struct.Edge, ptr %6, i32 0, i32 1
  %36 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %36, ptr %35, align 4, !tbaa !11
  %37 = load i32, ptr @tot, align 4, !tbaa !5
  %38 = add nsw i32 %37, 1
  store i32 %38, ptr @tot, align 4, !tbaa !5
  %39 = sext i32 %38 to i64
  %40 = getelementptr inbounds [4004 x %struct.Edge], ptr @e, i64 0, i64 %39
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %40, ptr align 4 %6, i64 8, i1 false), !tbaa.struct !12
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #5
  %41 = load i32, ptr @tot, align 4, !tbaa !5
  %42 = load i32, ptr %4, align 4, !tbaa !5
  %43 = sext i32 %42 to i64
  %44 = getelementptr inbounds [2002 x i32], ptr @pre, i64 0, i64 %43
  store i32 %41, ptr %44, align 4, !tbaa !5
  br label %45

45:                                               ; preds = %13
  %46 = load i32, ptr %2, align 4, !tbaa !5
  %47 = add nsw i32 %46, 1
  store i32 %47, ptr %2, align 4, !tbaa !5
  br label %8, !llvm.loop !13

48:                                               ; preds = %12
  call void @_Z3dfsii(i32 noundef 1, i32 noundef -1)
  %49 = load i32, ptr @k, align 4, !tbaa !5
  %50 = sext i32 %49 to i64
  %51 = getelementptr inbounds [2002 x i32], ptr getelementptr inbounds ([2002 x [2002 x i32]], ptr @g, i64 0, i64 1), i64 0, i64 %50
  %52 = load i32, ptr %51, align 4, !tbaa !5
  %53 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i32 noundef %52)
  ret i32 0
}

declare i32 @__isoc99_scanf(ptr noundef, ...) #4

declare i32 @printf(ptr noundef, ...) #4

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 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { 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 #4 = { "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 #5 = { 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, !6, i64 0}
!10 = !{!"_ZTS4Edge", !6, i64 0, !6, i64 4}
!11 = !{!10, !6, i64 4}
!12 = !{i64 0, i64 4, !5, i64 4, i64 4, !5}
!13 = distinct !{!13, !14}
!14 = !{!"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"

%struct.Edge = type { i32, i32 }

@n = external dso_local global i32, align 4
@k = external dso_local global i32, align 4
@tot = external dso_local local_unnamed_addr global i32, align 4
@pre = external dso_local local_unnamed_addr global [2002 x i32], align 16
@g = external dso_local local_unnamed_addr global [2002 x [2002 x i32]], align 16
@e = external dso_local local_unnamed_addr global [4004 x %struct.Edge], align 16
@.str = external hidden unnamed_addr constant [5 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [4 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 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull @n, ptr noundef nonnull @k)
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #4
  %4 = load i32, ptr @n, align 4, !tbaa !5
  %5 = icmp sgt i32 %4, 1
  br i1 %5, label %.lr.ph, label %._crit_edge

._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 -1)
  %6 = load i32, ptr @k, align 4, !tbaa !5
  %7 = sext i32 %6 to i64
  %8 = getelementptr inbounds [2002 x i32], ptr getelementptr inbounds (i8, ptr @g, i64 8008), i64 0, i64 %7
  %9 = load i32, ptr %8, align 4, !tbaa !5
  %10 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i32 noundef %9)
  ret i32 0

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.04 = phi i32 [ %27, %.lr.ph ], [ 1, %0 ]
  %11 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %1, ptr noundef nonnull %2)
  %12 = load i32, ptr %1, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [2002 x i32], ptr @pre, i64 0, i64 %13
  %15 = load i32, ptr %14, align 4, !tbaa !5
  %16 = load i32, ptr %2, align 4, !tbaa !5
  %17 = load i32, ptr @tot, align 4, !tbaa !5
  %18 = add nsw i32 %17, 1
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [4004 x %struct.Edge], ptr @e, i64 0, i64 %19
  store i32 %15, ptr %20, align 8, !tbaa !5
  %.sroa.42.0..sroa_idx = getelementptr inbounds i8, ptr %20, i64 4
  store i32 %16, ptr %.sroa.42.0..sroa_idx, align 4, !tbaa !5
  store i32 %18, ptr %14, align 4, !tbaa !5
  %21 = sext i32 %16 to i64
  %22 = getelementptr inbounds [2002 x i32], ptr @pre, i64 0, i64 %21
  %23 = load i32, ptr %22, align 4, !tbaa !5
  %24 = add nsw i32 %17, 2
  store i32 %24, ptr @tot, align 4, !tbaa !5
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds [4004 x %struct.Edge], ptr @e, i64 0, i64 %25
  store i32 %23, ptr %26, align 8, !tbaa !5
  %.sroa.4.0..sroa_idx = getelementptr inbounds i8, ptr %26, i64 4
  store i32 %12, ptr %.sroa.4.0..sroa_idx, align 4, !tbaa !5
  store i32 %24, ptr %22, align 4, !tbaa !5
  %27 = add nuw nsw i32 %.04, 1
  %28 = load i32, ptr @n, align 4, !tbaa !5
  %29 = icmp slt i32 %27, %28
  br i1 %29, label %.lr.ph, label %._crit_edge, !llvm.loop !9
}

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

; 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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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