// #pragma GCC optimize("O3")
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define N 1000000007
#define N2 998244353
#define Nmax 300005
#define INF (ll)1e18
#define pll pair<ll,ll>
#define mp make_pair
#define fi first
#define se second
#define vv vector
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(ll i=m;i<(n);i++)
#define repr(i,n) repr2(i,n,0)
#define repr2(i,m,n) for(ll i=m;i>=(n);i--)
#define get(n) ll (n); scanf("%lld",&(n));
#define get2(n,k) ll (n),(k); scanf("%lld%lld",&(n),&(k));
#define get3(n,m,k) ll (n),(m),(k); scanf("%lld%lld%lld",&(n),&(m),&(k));
#define gets(s) string (s); cin >> (s);
#define ALL(c) (c).begin(),(c).end()
#define fill_nums(A,n) vector<ll> A((n)); for(ll i=0;i<n;i++) scanf("%lld",&A[i]);
#define fill_edges(adj,m) for(ll i=0;i<m;i++) {ll a, b; scanf("%lld %lld",&a,&b); adj[a-1].pb(b-1); adj[b-1].pb(a-1);}
#define fill_direct(adj,m) for(ll i=0;i<m;i++) {ll a, b; scanf("%lld %lld",&a,&b); adj[a-1].pb(b-1);}
#define StarBurstStream ios_base::sync_with_stdio(false); cin.tie(0); //cout.tie(0);
#define pi 3.1415926535897L
#define db long double  /* print with %Lf */
#define EPS 1e-9
#define flu fflush(stdout)
#define imp {cout<<"No\n"; return 0;}
#define yup {cout<<"Yes\n"; return 0;}
#define debug_vec(vec,n) {rep(idxi,n) cout<<vec[idxi]<<" "; cout<<"\n";}
#define debug_pvec(vec,n) {rep(idxi,n) cout<<vec[idxi].fi<<"-"<<vec[idxi].se<<"  "; cout<<"\n";}
#define debug_set(seta) {cout<<seta.size()<<"\n"; for(auto idxi:seta) cout<<idxi<<" "; cout<<"\n";}
#define debug_map(mappa) {cout<<mappa.size()<<"\n";for(auto idxi:mappa) cout<<idxi.fi<<"-"<<idxi.se<<"  "; cout<<"\n";}
#define debug_vecvec(vec,n) {rep(idxi,n) {for(auto idxi2:vec[idxi]) cout<<idxi2<<" "; cout<<"\n";}}
 
// LOOK AT THESE BEFORE SUBMISSION
// LOOK AT THESE BEFORE SUBMISSION
// ============================================================
// Nmax value and is index access offset taking it beyond Nmax.
// Precision error in case of real numbers.
// N vs N2 chosen correctly.
// Modulo applied everywhere.
// Flush in case of interactive.
// Don't erase value in multiset.
// Check for array indices out of bound (in pre or suff sums).
// Correct return value for functions.
// Confirm the letter case of yes and no.
// Dont paste code two times in the text file.
// ============================================================


int main() {

    get(n);
    gets(s);
    // ll n = s.size();

    vv<ll> A;
    for(auto i:s) A.pb(i-'0');

    // while(A.size()) {
    //     vv<ll> temp;
    //     rep(i,A.size()-1)   
    //         temp.pb(abs(A[i]-A[i+1]));

    //     A = temp;
    //     debug_vec(A, A.size());
    // }


    vector<ll> facts(n-1,0);
    rep(i,n-1) {
        ll m = n-2;
        if((i^(m-i)) == m) facts[i] = 1;
    }
    // debug_vec(facts, facts.size());

    // A.clear(); for(auto i:s) A.pb(i-'0');
    vv<ll> temp;
    rep(i,A.size()-1)   
        temp.pb(abs(A[i]-A[i+1]));
    A = temp;
    // debug_vec(A, A.size())

    ll v1 = 0, v2 = 0, f = 0;
    rep(i,n-1) {
        if(A[i]==1) f = 1;
        v1 = v1^(facts[i]*(A[i]==1));
    }

    rep(i,n-1)
        v2 = v2^(facts[i]*(A[i]==2));
    v2 = v2*2;


    if(f) cout<<v1<<endl;
    else cout<<v2<<endl;
    return 0;  
}   


Measured memory_bytes: 31092