// yukicoder: No.346 チワワ数え上げ問題
// 2019.4.15 bal4u

#include <stdio.h>

#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif
int ins(char *s)
{
	char *p = s;
	do *s = gc();
	while (*s++ > ' ');
	*--s = 0;
	return s - p;
}

char S[100005];

int main()
{
	int w;
	long long ans;
	char *p;

	p = S + ins(S), w = 0, ans = 0;
	while (--p >= S) {
		if (*p == 'w') w++;
		else if (*p == 'c') ans += w*(w-1) >> 1;
	}
	printf("%lld\n", ans);
	return 0;
}