#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int INF = int(1e9)+1;
struct segtree {
vector<int> tree;
int n;
segtree(int n) : n(n) {
tree.resize(2*n, INF);
}
void upd(int u, int k) {
tree[u += n] = k;
for (u /= 2; u >= 1; u /= 2) {
tree[u] = min(tree[2*u], tree[2*u+1]);
}
}
int qry(int l, int r) {
int res = INF;
l += n; r += n;
while (l <= r) {
if (l % 2 == 1) res = min(res, tree[l++]);
if (r % 2 == 0) res = min(res, tree[r--]);
l /= 2; r /= 2;
}
return res;
}
};
void solve() {
int n, q; cin >> n >> q;
segtree st(n+1);
for (int i = 1; i <= q; i++) {
char c; cin >> c;
int a, b; cin >> a >> b;
if (c == 'M') {
st.upd(b, a);
} else {
int lo = b, hi = n;
while (lo < hi) {
int mid = (lo + hi) / 2;
if (st.qry(b, mid) <= a) hi = mid;
else lo = mid+1;
}
cout << (st.qry(b, lo) > a ? -1 : lo) << "\n";
}
}
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
int t = 1;
// cin >> t;
while (t--) solve();
return 0;
}
