块长可能不对，就不要管了

#include <bits/stdc++.h>
using namespace std;

const int N = 1e6 + 9;

#define gc getchar
inline int read() {
	int c = gc(), t = 1, n = 0;
	while(isspace(c)) { c = gc(); }
	if(c == '-') { t = -1, c = gc(); }
	while(isdigit(c)) { n = n * 10 + c - '0', c = gc(); }
	return n * t;
}
#undef gc

struct change {
	int id,last,now;
}p[N];

struct node {
	int l,r,pre,id,bl,br;
}q[N];

int n,m,tota,totb,len,l,r,t,nl,nr,nt;
int a[N],ans[N],cnt,sum[N];
char ch;

bool cmp(node u,node v) {
	if(u.bl != v.bl) return u.bl < v.bl;
	else {
		if(u.br != v.br) return u.br < v.br;
		else return u.pre < v.pre; 
	}
}

inline void del(int x) {
	if(--sum[a[x]] == 0) --cnt;
}

inline void add(int x) {
	if(++sum[a[x]] == 1) ++cnt;
}

int main() {
	n = read(); m = read(); len = pow(n,2.0 / 3);
	for(int i = 1;i <= n;i++) a[i] = read();
	for(int i = 1;i <= m;i++) {
		do ch = getchar(); while(ch != 'Q' && ch != 'R');
		if(ch == 'R') {
			p[++tota].id = read(); p[tota].now = read();
			p[tota].last = a[p[tota].id]; a[p[tota].id] = p[tota].now;
		}else {
			q[++totb].id = i; q[totb].l = read(); q[totb].r = read();
			q[totb].pre = tota;  q[totb].bl = (q[totb].l - 1) / len + 1; q[totb].br = (q[totb].r - 1) / len + 1;
		}
	}
	sort(q + 1,q + totb + 1,cmp);
	l = 1; r = 0; t = 0; cnt = 0;
	for(int i = 1;i <= m;i++) {
		nl = q[i].l; nr = q[i].r; nt = q[i].pre;
		while(l < nl) del(l++);
		while(l > nl) add(--l);
		while(r > nr) del(r--);
		while(r < nr) add(++r);
		while(t < nt) {	// go forward
			++t;
			int alpha = p[t].id;
			if(l <= alpha && alpha <= r) del(alpha);
			a[alpha] = p[t].now;
			if(l <= alpha && alpha <= r) add(alpha);
		}
		while(t > nt) {	// go back
			int alpha = p[t].id;
			if(l <= alpha && alpha <= r) del(alpha);
			a[alpha] = p[t].last;
			if(l <= alpha && alpha <= r) add(alpha);
			--t;
		}
		ans[q[i].id] = cnt;
	}
	for(int i = 1;i <= totb;i++) {
		printf("%d\n",ans[i]);
	}
	return 0;
}