1975 {
1976 int n;
1977 cin >> n;
1978 auto *cow = new char[n];
1979 auto *c = new int[n];
1980 auto *w = new int[n];
1981 c[0] = 0;
1982 w[n - 1] = 0;
1983 for(int i = 0; i < n; i++) {
1984 cin >> cow[i];
1985 if(i >= 1) {
1986 c[i] = c[i - 1];
1987 if(cow[i - 1] == 'C') {
1988 c[i]++;
1989 }
1990 }
1991 }
1992 for(int i = n - 2; i >= 0; i--) {
1993 w[i] = w[i + 1];
1994 if(cow[i + 1] == 'W') {
1995 w[i]++;
1996 }
1997 }
1998 unsigned long count = 0;
1999 for(int i = 0; i < n; i++) {
2000 if(cow[i] == 'O') {
2001 count += c[i] * w[i];
2002 }
2003 }
2004 cout << count;
2005 delete[] w;
2006 delete[] c;
2007 delete[] cow;
2008 return 0;
2009 }