#include<bits/stdc++.h>
using namespace std;

// Optimization

//#pragma GCC optimize("O3")
#define endl '\n'

// Shortcut

// #define int long long
#define eb emplace_back
#define pb push_back
#define pob pop_back
#define mp make_pair
#define upb upper_bound
#define lwb lower_bound
#define fi first
#define se second
#define For(i, l, r) for (int i = l; i < r; i++)
#define ForE(i, l, r) for (int i = l; i <= r; i++)
#define Ford(i, r, l) for (int i = r; i > l; i--)
#define FordE(i, r, l) for (int i = r; i >= l; i--)
#define Fora(i, a) for (auto i : a)

// I/O & Debug

#define PrintV(a) Fora(iiii, a) cout << iiii << ' '; cout << endl;
#define PrintVl(a) Fora(iiii, a) cout << iiii << endl;
#define PrintA(a, l, r) for (int iiii = l; iiii <= r; iiii++) cout << a[iiii] << ' '; cout << endl;
#define PrintAl(a, l, r) for (int iiii = l; iiii <= r; iiii++) cout << a[iiii] << endl;
#define Ptest(x) return cout << x, 0;
#define gl(s) getline(cin, s);
#define setpre(x) fixed << setprecision(x)
/*
#define debug(args...){ string _sDEB = #args; replace(_sDEB.begin(), _sDEB.end(), ',', ' '); stringstream _ssDEB(_sDEB); istream_iterator<string> _itDEB(_ssDEB); DEB(_itDEB, args); }
void DEB(istream_iterator<string> it) {}
template<typename T, typename... Args>
void DEB(istream_iterator<string> it, T a, Args... args){
    cout << *it << " = " << a << endl;
    DEB(++it, args...);
}
*/

// Functions

//#define isvowel(a) (a == 'a' || a == 'e' || a == 'i' || a == 'o' || a == 'u')
#define bend(a) a.begin(), a.end()
#define rbend(a) a.rbegin(), a.rend()
#define mset(a) memset(a, 0, sizeof(a))
#define mset1(a) memset(a, 1, sizeof(a))
#define msetn1(a) memset(a, -1, sizeof(a))
#define msetinf(a) memset(a, 0x3f, sizeof(a))
#define gcd __gcd
#define __builtin_popcount __builtin_popcountll
//mt19937 rando(chrono::steady_clock::now().time_since_epoch().count());

// Data Structure

#define pque priority_queue
#define mts multiset
#define y0 _y0_
#define y1 _y1_
#define div divi
typedef long long ll;
typedef long double ld;
typedef vector <int> vi;
typedef vector <ll> vll;
typedef vector <ld> vld;
typedef vector <string> vs;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef vector <vi > vvi;
typedef vector <vll > vvll;
typedef vector <pii > vpii;
typedef vector <pll > vpll;

const int N = 1e6 + 5, mod = 1e9 + 7, mod1 = 998244353, mod2 = 1e9 + 9, inf = 1e9 + 7;
const ll infll = 1e18 + 7;

int nCrModpDP(int n, int r, int p) 
{ 
    // The array C is going to store last row of 
    // pascal triangle at the end. And last entry 
    // of last row is nCr 
    int C[r+1]; 
    memset(C, 0, sizeof(C)); 
  
    C[0] = 1; // Top row of Pascal Triangle 
  
    // One by constructs remaining rows of Pascal 
    // Triangle from top to bottom 
    for (int i = 1; i <= n; i++) 
    { 
        // Fill entries of current row using previous 
        // row values 
        for (int j = min(i, r); j > 0; j--) 
  
            // nCj = (n-1)Cj + (n-1)C(j-1); 
            C[j] = (C[j] + C[j-1])%p; 
    } 
    return C[r]; 
} 
  
// Lucas Theorem based function that returns nCr % p 
// This function works like decimal to binary conversion 
// recursive function.  First we compute last digits of 
// n and r in base p, then recur for remaining digits 
int nCrModpLucas(int n, int r, int p) 
{ 
   // Base case 
   if (r==0) 
      return 1; 
  
   // Compute last digits of n and r in base p 
   int ni = n%p, ri = r%p; 
  
   // Compute result for last digits computed above, and 
   // for remaining digits.  Multiply the two results and 
   // compute the result of multiplication in modulo p. 
   return (nCrModpLucas(n/p, r/p, p) * // Last digits of n and r 
           nCrModpDP(ni, ri, p)) % p;  // Remaining digits 
} 

int n;
int a[N];

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    cin >> n;
    ForE(i, 1, n){
        char c; cin >> c;
        a[i] = c - '0';
    }
    if (n == 1) Ptest(a[1]);
    n--;
    ForE(i, 1, n){
        a[i] = abs(a[i] - a[i + 1]);
    }
    bool ck = 0;
    ForE(i, 1, n){
        if (a[i] == 1){
            ck = 1;
            break;
        }
    }
    if (ck){
        ForE(i, 1, n){
            if (a[i] == 2) a[i] = 0;
        }
    }
    else{
        ForE(i, 1, n){
            if (a[i] == 2) a[i] = 1;
        }
    }
    // cout << n << endl;
    // PrintA(a, 1, n);
    int ans = 0;
    ForE(i, 1, n){
        if (nCrModpLucas(n - 1, i - 1, 2)) ans ^= a[i];
    }
    if (!ck && ans) ans = 2;
    cout << ans;
}

/*
==================================+
INPUT:                            |
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------------------------------    |
==================================+
OUTPUT:                           |
------------------------------    |

------------------------------    |
==================================+
*/



Measured memory_bytes: 4224