#pragma GCC target("sse,sse2,sse3,ssse3,sse4,avx,avx2,fma")
#include<bits/stdc++.h>
#pragma GCC optimize("Ofast,unroll-loops")
using namespace std;
#define ll long long
#define int ll
#define ull unsigned long long
#define ld long double
#define rep(a) rep1(i,a)
#define rep1(i,a) rep2(i,0,a)
#define rep2(i,b,a) for(int i=(b); i<((int)(a)); i++)
#define rep3(i,b,a) for(int i=(b); i>=((int)(a)); i--)
#define all(a) a.begin(),a.end()
#define pii pair<int,int>
#define pb push_back
//#define inf 1010000000
#define inf 4000000000000000000
#define eps 1e-9
#define sz(a) ((int)a.size())
#define pow2(x) (1ll<<(x))
#define ceiling(a,b) (((a)+(b)-1)/(b))
#ifdef i_am_noob
#define bug(...) cerr << "#" << __LINE__ << ' ' << #__VA_ARGS__ << "- ", _do(__VA_ARGS__)
template<typename T> void _do(T && x) {cerr << x << endl;}
template<typename T, typename ...S> void _do(T && x, S&&...y) {cerr << x << ", "; _do(y...);}
#else
#define bug(...) 826
#endif
inline char readchar(){
const int maxn=1000000;
static char buf[maxn],*p=buf,*q=buf;
if(p==q&&(q=(p=buf)+fread(buf,1,maxn,stdin))==buf) return EOF;
else return *p++;
}
inline int readint(){
int c=readchar(),x=0,neg=0;
while((c<'0'||c>'9')&&c!='-'&&c!=EOF) c=readchar();
if(c=='-') neg=1,c=readchar();
while(c>='0'&&c<='9') x=(x<<3)+(x<<1)+(c^'0'),c=readchar();
return neg?-x:x;
}
const int Mod=1000000007,Mod2=998244353;
const int MOD=Mod;
const int maxn=1000005;
//i_am_noob
int n,dp[2][maxn],pre0[maxn],pre1[maxn],minn0=inf,minn1=inf,minn2=inf,minn3=inf;
bool a[maxn],b[maxn];
signed main(){
ios_base::sync_with_stdio(0),cin.tie(0);
#ifdef i_am_noob
freopen("input1.txt","r",stdin);
freopen("output1.txt","w",stdout);
freopen("output2.txt","w",stderr);
#endif
cin >> n;
a[0]=b[0]=0;
rep(n){
char c;
cin >> c;
a[i+1]=c=='1';
}
rep(n){
char c;
cin >> c;
b[i+1]=c=='1';
}
rep(n+1) a[i]^=b[i];
rep(n) bug(i+1,a[i+1]);
dp[0][0]=0,dp[1][0]=1;
pre0[0]=pre1[0]=0;
rep2(i,1,n+1){
pre0[i]=pre0[i-1],pre1[i]=pre1[i-1];
if(b[i]&&!b[i-1]) pre0[i]++;
if((b[i-1]||i==1)&&!b[i]) pre1[i]++;
bug(pre0[i],pre1[i]);
}
minn0=dp[b[1]][0]-pre0[1];
minn1=dp[b[1]^1][0]+(b[1]==1)-pre0[1];
minn2=dp[b[1]^1][0]-pre1[1];
minn3=dp[b[1]][0]+(b[1]==0)-pre1[1];
rep2(i,1,n+1){
dp[0][i]=dp[1][i]=inf;
bug(minn0,minn1,minn2,minn3);
dp[b[i]][i]=min(minn0,minn1)+pre0[i]+1;
dp[b[i]^1][i]=min(minn2,minn3)+pre1[i]+1;
dp[a[i]][i]=min(dp[a[i]][i],min(dp[a[i]][i-1],dp[a[i]^1][i-1]+(a[i]==1)));
minn0=min(minn0,dp[b[i+1]][i]-pre0[i+1]);
minn1=min(minn1,dp[b[i+1]^1][i]+(b[i+1]==1)-pre0[i+1]);
minn2=min(minn2,dp[b[i+1]^1][i]-pre1[i+1]);
minn3=min(minn3,dp[b[i+1]][i]+(b[i+1]==0)-pre1[i+1]);
bug(i,dp[0][i],dp[1][i]);
}
cout << min(dp[0][n],dp[1][n]) << "\n";
return 0;
}
