#include <bits/stdc++.h>
#define FOR(i,a,b) for(ut i=(a);i<(int)(b);i++)
#define REP(i,b) FOR(i,0,b)
#define ALL(c) c.begin(),c.end()
#define PB push_back
#define cat //cout << __LINE__ << endl;
using namespace std;
typedef long long LL;
typedef long double ld;
typedef int ut;
typedef vector<ut> VI;
typedef pair<ut,ut> pr;
typedef pair<ut,pr> ppr;
typedef vector<pr> Vpr;
typedef vector<ppr> Vppr;
typedef priority_queue<pr,Vpr,greater<pr> > PQ;
const int SIZE=2*1e5;
const int INF=1LL<<30;
const LL p=7+1e9;
int main(){
	string s;
	cin >> s;
	int ans=0;
	char now='A';
	REP(i,s.size()){
		if(now>=s[i]) ans++;
		now=s[i];
	}
	cout << ans << endl;
	return 0;
}