#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll INF = 2000000005LL;
struct SegTree {
int n;
vector<ll> st;
SegTree(int _n=0) { init(_n); }
void init(int _n) {
n = _n;
st.assign(4*n+4, INF);
}
void update(int p, int l, int r, int pos, ll val) {
if (l == r) {
st[p] = val;
return;
}
int m = (l + r) >> 1;
if (pos <= m) update(p<<1, l, m, pos, val);
else update(p<<1|1, m+1, r, pos, val);
st[p] = min(st[p<<1], st[p<<1|1]);
}
void update(int pos, ll val) {
update(1, 1, n, pos, val);
}
int find_first(int p, int l, int r, int ql, ll Y) {
if (r < ql || st[p] > Y) return -1;
if (l == r) return l;
int m = (l + r) >> 1;
int res = -1;
if (ql <= m) {
res = find_first(p<<1, l, m, ql, Y);
if (res != -1) return res;
}
return find_first(p<<1|1, m+1, r, ql, Y);
}
int find_first(int ql, ll Y) {
return find_first(1, 1, n, ql, Y);
}
};
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int N, Q;
cin >> N >> Q;
SegTree st(N);
while (Q--) {
char type;
cin >> type;
if (type == 'M') {
ll X;
int A;
cin >> X >> A;
st.update(A, X);
} else if (type == 'D') {
ll Y;
int B;
cin >> Y >> B;
int ans = st.find_first(B, Y);
if (ans == -1) cout << -1 << "\n";
else cout << ans << "\n";
}
}
return 0;
}
