#include <bits/stdc++.h>
using namespace std;
int n;
char s[5010];
vector<int> nextt;
int main() {
	scanf("%d",&n);
	for(int i=0;i<=n;i++) scanf("%c",&s[i]);
	for(int i=1;i<=n;i++) if(s[i]==s[i+1]) nextt.push_back(i);
	if(nextt.size()%2==1) nextt.push_back(n);
	printf("%d",nextt.size()/2);
	if(nextt.size()!=0) printf("\n");
	for(int i=0;i<nextt.size();i+=2) {
		printf("%d %d BCA",nextt[i]+1,nextt[i+1]);
		if(i+1!=nextt.size()-1) printf("\n");
	}
	return 0;
}

WA完了，对不出来。