#include <iostream>
#include <map>
using namespace std;

int main() {
	int cnt = 0;
	char buf;
	map<int, long long> mp;
	mp[0] = 1;
	while(cin >>buf) {
		if(buf=='R')
			cnt++;
		else
			cnt--;
		mp[cnt]++;
	}
	long long answer = 0;
	for(auto e: mp) {
		answer += e.second*(e.second-1)/2;
	}
	cout <<answer;
}