LIGHTS - Lights
Tác giả: RR
Ngôn ngữ: Pascal
{$R+,Q+}
const
FINP='';
FOUT='';
MAXN=10001;
var
n,kq:longint;
a,b:array[0..MAXN] of integer;
procedure inp;
var
f:text;
ch:char;
i:longint;
begin
assign(f,FINP); reset(f);
readln(f,n);
for i:=1 to n do
begin
read(f,ch);
if ch='0' then a[i]:=0 else a[i]:=1;
end;
readln(f);
for i:=1 to n do
begin
read(f,ch);
if ch='0' then b[i]:=0 else b[i]:=1;
end;
close(f);
end;
procedure ans;
var
f:text;
begin
assign(f,FOUT); rewrite(f);
writeln(f,kq);
close(f);
end;
function check(a,b,c:byte):boolean;
begin
check:=true;
if (a=0) and (b=1) and (c=0) then exit;
if (a=1) and (b=0) and (c=1) then exit;
check:=false;
end;
procedure solve;
var
i:longint;
begin
kq:=0;
for i:=1 to n do
if check(a[i-1],a[i],a[i+1]) and check(b[i-1],b[i],b[i+1]) then
begin
a[i]:=1-a[i];
b[i]:=1-b[i];
inc(kq);
end;
for i:=1 to n do
if (a[i-1]=0) and (a[i]=1) then inc(kq);
for i:=1 to n do
if (b[i-1]=0) and (b[i]=1) then inc(kq);
end;
begin
inp;
solve;
ans;
end.