#include<bits/stdc++.h>
using namespace std;
class SegTree {
private:
vector<int> st;
int sz;
void update(int pos, int val, int id, int l, int r) {
if (l == r) { st[id] = val; return; }
int m = (l + r) >> 1;
if (m >= pos) update(pos, val, id << 1, l, m);
else update(pos, val, id << 1 | 1, m + 1, r);
st[id] = min(st[id << 1], st[id << 1 | 1]);
}
int query(int val, int l, int r, int id, int tl, int tr) {
if (r < tl || l > tr) return -1;
if (l <= tl && tr <= r) {
if (st[id] > val) return -1;
if (tl == tr) return st[id] > val ? -1 : tl;
}
int m = (tl + tr) >> 1;
int tmp = query(val, l, r, id << 1, tl, m);
if (tmp != -1) return tmp;
return query(val, l, r, id << 1 | 1, m + 1, tr);
}
public:
SegTree(int n) {
st.assign(n << 2 | 1, 1e9 + 3);
sz = n;
}
void update(int pos, int val) { update(pos, val, 1, 1, sz); }
int query(int val, int l) { return query(val, l, sz, 1, 1, sz); }
};
int main() {
int n, m; cin >> n >> m;
SegTree s(n);
while (m--) {
char op; int a, b;
cin >> op >> a >> b;
if (op == 'M') s.update(b, a);
else cout << s.query(a, b) << '\n';
}
return 0;
}
