#import <stdio.h>
int main() {
    int n;
    scanf("%d ", &n);
    char A[101];
    char B[101];
    char C[101];
    scanf("%s", A);
    scanf("%s", B);
    scanf("%s", C);
    int ans = 0;
    for (int i = 0; i < n; i++) {
        char a = A[i];
        char b = B[i];
        char c = C[i];
        if (a != b && b != c && c != a) ans += 2;
        else if (!(a==b && b==c))
            ans++;
    }
    printf("%d\n", ans);
}

; ModuleID = '/data/TheStack_IR/OJ_Samples/Collated/ObjectiveC/Source_380/source.m'
source_filename = "/data/TheStack_IR/OJ_Samples/Collated/ObjectiveC/Source_380/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 [4 x i8] c"%d \00", align 1
@.str.1 = private unnamed_addr constant [3 x i8] c"%s\00", align 1
@.str.2 = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1

; Function Attrs: minsize nofree nounwind optsize uwtable
define dso_local i32 @main() local_unnamed_addr #0 {
entry:
  %n = alloca i32, align 4
  %A = alloca [101 x i8], align 16
  %B = alloca [101 x i8], align 16
  %C = alloca [101 x i8], align 16
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %n) #4
  %call = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %n) #5
  call void @llvm.lifetime.start.p0(i64 101, ptr nonnull %A) #4
  call void @llvm.lifetime.start.p0(i64 101, ptr nonnull %B) #4
  call void @llvm.lifetime.start.p0(i64 101, ptr nonnull %C) #4
  %call1 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef nonnull %A) #5
  %call3 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef nonnull %B) #5
  %call5 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef nonnull %C) #5
  %0 = load i32, ptr %n, align 4, !tbaa !5
  %smax = call i32 @llvm.smax.i32(i32 %0, i32 0)
  %wide.trip.count = zext i32 %smax to i64
  br label %for.cond

for.cond:                                         ; preds = %for.body, %entry
  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
  %ans.0 = phi i32 [ %ans.1, %for.body ], [ 0, %entry ]
  %exitcond.not = icmp eq i64 %indvars.iv, %wide.trip.count
  br i1 %exitcond.not, label %for.cond.cleanup, label %for.body

for.cond.cleanup:                                 ; preds = %for.cond
  %call34 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2, i32 noundef %ans.0) #5
  call void @llvm.lifetime.end.p0(i64 101, ptr nonnull %C) #4
  call void @llvm.lifetime.end.p0(i64 101, ptr nonnull %B) #4
  call void @llvm.lifetime.end.p0(i64 101, ptr nonnull %A) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %n) #4
  ret i32 0

for.body:                                         ; preds = %for.cond
  %arrayidx = getelementptr inbounds [101 x i8], ptr %A, i64 0, i64 %indvars.iv
  %1 = load i8, ptr %arrayidx, align 1, !tbaa !9
  %arrayidx7 = getelementptr inbounds [101 x i8], ptr %B, i64 0, i64 %indvars.iv
  %2 = load i8, ptr %arrayidx7, align 1, !tbaa !9
  %arrayidx9 = getelementptr inbounds [101 x i8], ptr %C, i64 0, i64 %indvars.iv
  %3 = load i8, ptr %arrayidx9, align 1, !tbaa !9
  %cmp11.not = icmp eq i8 %1, %2
  %cmp15.not = icmp eq i8 %2, %3
  %or.cond = select i1 %cmp11.not, i1 true, i1 %cmp15.not
  %cmp20.not = icmp eq i8 %3, %1
  %or.cond48 = select i1 %or.cond, i1 true, i1 %cmp20.not
  %or.cond49 = select i1 %cmp11.not, i1 %cmp15.not, i1 false
  %not.or.cond49 = xor i1 %or.cond49, true
  %inc = zext i1 %not.or.cond49 to i32
  %ans.1.v = select i1 %or.cond48, i32 %inc, i32 2
  %ans.1 = add nuw nsw i32 %ans.1.v, %ans.0
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  br label %for.cond
}

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

; Function Attrs: minsize nofree nounwind optsize
declare noundef i32 @__isoc99_scanf(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

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

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smax.i32(i32, i32) #3

attributes #0 = { minsize nofree nounwind optsize 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 = { minsize nofree nounwind optsize "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 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
attributes #4 = { nounwind }
attributes #5 = { minsize optsize }

!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 = !{!7, !7, i64 0}
