#include<iostream>
#include<string>
using namespace std;
int main()
{
	int n, k, i=0;
	string s;
	getline(cin, s);
	k = 0;

	while (s[i] != ' ') {
		n = s.find(' ');
		if (s[i] == s[n - 1]) {
			k++;
			i += n - 1;
		}
			s.erase(i, n);

	}
	cout << k << endl;
}