#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;

typedef int _loop_int;
#define REP(i,n) for(_loop_int i=0;i<(_loop_int)(n);++i)
#define FOR(i,a,b) for(_loop_int i=(_loop_int)(a);i<(_loop_int)(b);++i)
#define FORR(i,a,b) for(_loop_int i=(_loop_int)(b)-1;i>=(_loop_int)(a);--i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG2(x,y) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

const ll MOD = 1000000007ll;
#define FIX(a) ((a)%MOD+MOD)%MOD

int main() {
    ios::sync_with_stdio(false); cin.tie(0);
    int n;
    cin>>n;

    string s;
    //string tmp;
    queue<char> q;
    int ans = 0;
    REP(i,n){
        char c;
        cin>>c;
        if(c=='3'||c=='5'||c=='7'){
            ans++;
            continue;
        }

        s += c;
    }

    char tmp ='0';
    REP(i,s.size()){
        if(s[i]=='1'){
            if(tmp=='1'){
                ans++;
                tmp='0';
            }else{
                tmp='1';
            }
        }else if(s[i]=='9'){
            if(tmp=='1'){
                ans++;
                tmp='0';
            }
        }else{
            //cout<<"Error!"<<endl;
        }
    }
    cout << ans << endl;
    return 0;
}