#include <cmath>
#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <set>
#include <map>
#include <list>
#include <time.h>
#include <math.h>
#include <random>
#include <deque>
#include <queue>
#include <cassert>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <bitset>
#include <sstream>
#include <chrono>
#include <cstring>
#include <string>

using namespace std;

#define X first
#define Y second
#define pb push_back
#define mp make_pair
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(),(x).end()
#define PI 3.14159265358979323846

typedef long long ll;

const int maxn = 1e5 + 228;
const int mod = 1e9 + 7;



int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    string s;
    cin >> s;
    int res = 0;
    while(true){
        int l = -1;
        int r = -1;
        int maxi = 1;
        int ans = 1;
        cout << s << endl;
        for(int i = 1; i < s.size(); ++i){
            if(s[i] - s[i - 1] == 1)
                ans++;
            else{
                if(ans > maxi){
                    r = i - 1;
                    l = i - ans;
                    maxi = ans;
                }
            }
        }
        cout << l << " " << r << endl;
        string xd = "";
        if(l == -1)
            break;
        res += maxi - 1;
        for(int i = 0; i < s.size(); ++i){
            if(i > l && i <= r)
                continue;
            else
                xd += s[i];
        }
    }
    cout << res << endl;

}