#import <stdio.h>
#import <stdlib.h>
typedef long long INT;
int compare_int(const void *a, const void *b) {
    return *(int*)a - *(int*)b;
}
int main(){
    INT n;
    scanf("%lld",&n);
    INT d[100001] = {0};
    for(int i=0;i<n;i++){
        scanf("%lld",d+i);
    }
    qsort(d, n, sizeof(INT), compare_int);
    printf("%lld",d[n/2]-d[n/2-1]);
}

; ModuleID = '/data/TheStack_IR/OJ_Samples/Collated/ObjectiveC/Source_247/source.m'
source_filename = "/data/TheStack_IR/OJ_Samples/Collated/ObjectiveC/Source_247/source.m"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"

@.str = private unnamed_addr constant [5 x i8] c"%lld\00", align 1

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: read) uwtable
define dso_local i32 @compare_int(ptr nocapture noundef readonly %a, ptr nocapture noundef readonly %b) #0 {
entry:
  %0 = load i32, ptr %a, align 4, !tbaa !5
  %1 = load i32, ptr %b, align 4, !tbaa !5
  %sub = sub nsw i32 %0, %1
  ret i32 %sub
}

; Function Attrs: nofree nounwind uwtable
define dso_local i32 @main() local_unnamed_addr #1 {
entry:
  %n = alloca i64, align 8
  %d = alloca [100001 x i64], align 16
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %n) #6
  %call = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %n)
  call void @llvm.lifetime.start.p0(i64 800008, ptr nonnull %d) #6
  call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 dereferenceable(800008) %d, i8 0, i64 800008, i1 false)
  %0 = load i64, ptr %n, align 8, !tbaa !9
  %cmp10 = icmp sgt i64 %0, 0
  br i1 %cmp10, label %for.body, label %for.cond.cleanup

for.cond.cleanup:                                 ; preds = %for.body, %entry
  %.lcssa = phi i64 [ %0, %entry ], [ %4, %for.body ]
  call void @qsort(ptr noundef nonnull %d, i64 noundef %.lcssa, i64 noundef 8, ptr noundef nonnull @compare_int) #6
  %1 = load i64, ptr %n, align 8, !tbaa !9
  %div = sdiv i64 %1, 2
  %arrayidx = getelementptr inbounds [100001 x i64], ptr %d, i64 0, i64 %div
  %2 = load i64, ptr %arrayidx, align 8, !tbaa !9
  %sub = add nsw i64 %div, -1
  %arrayidx5 = getelementptr inbounds [100001 x i64], ptr %d, i64 0, i64 %sub
  %3 = load i64, ptr %arrayidx5, align 8, !tbaa !9
  %sub6 = sub nsw i64 %2, %3
  %call7 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str, i64 noundef %sub6)
  call void @llvm.lifetime.end.p0(i64 800008, ptr nonnull %d) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %n) #6
  ret i32 0

for.body:                                         ; preds = %entry, %for.body
  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
  %add.ptr = getelementptr inbounds i64, ptr %d, i64 %indvars.iv
  %call2 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %add.ptr)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %4 = load i64, ptr %n, align 8, !tbaa !9
  %cmp = icmp sgt i64 %4, %indvars.iv.next
  br i1 %cmp, label %for.body, label %for.cond.cleanup
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

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

; Function Attrs: mustprogress nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #4

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nofree
declare void @qsort(ptr noundef, i64 noundef, i64 noundef, ptr nocapture noundef) local_unnamed_addr #5

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

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: read) 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 = { nofree 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 #2 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { mustprogress nocallback nofree nounwind willreturn memory(argmem: write) }
attributes #5 = { nofree "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 #6 = { nounwind }

!llvm.linker.options = !{}
!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 = !{!"Ubuntu clang version 18.0.0 (++20231007042255+8abb2ace888b-1~exp1~20231007042414.1230)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"long long", !7, i64 0}
