#import <stdio.h>
typedef long long INT;
int main(){
    INT N,M;
    scanf("%lld %lld",&N,&M);
    INT result = 0;
    if (M<=2*N) {
        result = M/2;
    } else {
        result = N;
        M -= 2*N;
        result += M/4;
    }
    printf("%lld", result);
}

; ModuleID = '/data/TheStack_IR/OJ_Samples/Collated/ObjectiveC/Source_828/source.m'
source_filename = "/data/TheStack_IR/OJ_Samples/Collated/ObjectiveC/Source_828/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 [10 x i8] c"%lld %lld\00", align 1
@.str.1 = private unnamed_addr constant [5 x i8] c"%lld\00", align 1

; Function Attrs: nofree nounwind uwtable
define dso_local i32 @main() local_unnamed_addr #0 {
entry:
  %N = alloca i64, align 8
  %M = alloca i64, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %N) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %M) #3
  %call = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %N, ptr noundef nonnull %M)
  %0 = load i64, ptr %M, align 8, !tbaa !5
  %1 = load i64, ptr %N, align 8, !tbaa !5
  %mul = shl nsw i64 %1, 1
  %cmp.not = icmp sgt i64 %0, %mul
  br i1 %cmp.not, label %if.else, label %if.then

if.then:                                          ; preds = %entry
  %div = sdiv i64 %0, 2
  br label %if.end

if.else:                                          ; preds = %entry
  %sub = sub nsw i64 %0, %mul
  store i64 %sub, ptr %M, align 8, !tbaa !5
  %div2 = sdiv i64 %sub, 4
  %add = add nsw i64 %div2, %1
  br label %if.end

if.end:                                           ; preds = %if.else, %if.then
  %result.0 = phi i64 [ %div, %if.then ], [ %add, %if.else ]
  %call3 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i64 noundef %result.0)
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %M) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %N) #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 = { 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 #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.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 = !{!"long long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
