#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 2e5 + 10, INF = 1e18, MOD = 1e9 + 7;
typedef pair<int, int> PII;
typedef unsigned long long ull;
int dx[] = {0, 0, 1, -1}, dy[] = {1, -1, 0, 0};
int arr[N], brr[N];
bool st[N];
int n, m, k;

void solve()
{
	cin >> n;
	string a,b;
	cin >> a >> b;
	int ans[3][3] = {{0,1,0},{1,1,1},{0,1,0}};
	int x = a[n - 1] - '0', y = b[n - 1] - '0';
	for(int i = 0; i < n; i ++){
		int x = a[i] - '0', y = b[i] - '0';
		if(!(x | y)){
			cout << 0;
			return;
		}
	}
	cout << ans[x][y];
}

signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int T = 1;
//	cin >> T;
	while (T --)	solve();
	return 0;
}