#include <iostream>
#include <vector>
#include <algorithm>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <climits>
#include <array>
using namespace std;
using ll = long long;
vector<int> t;
/*
void build(int ind, int tl, int tr) {
if (tl == tr) t[ind] = a[tl];
else {
int tm = (tl + tr) / 2;
build(ind * 2, tl, tm);
build(ind * 2 + 1, tm + 1, tr);
t[ind] = min(t[ind * 2], t[ind * 2 + 1]);
}
}
*/
void update(int x, int val, int ind, int tl, int tr) {
if (tl == tr) t[ind] = val;
else {
int tm = (tl + tr) / 2;
if(x<=tm) update(x, val, ind * 2, tl, tm);
else update(x, val, ind * 2 + 1, tm+1, tr);
t[ind] = min(t[ind * 2], t[ind * 2 + 1]);
}
}
int query(int l, int r, int tl, int tr, int ind) {
if (tr<l || tl>r) return INT_MAX;
if ((tl == tr) ||(l <= tl && r >= tr)) return t[ind];
else {
int tm = (tl + tr) / 2;
return min(query(l, r, tl, tm, ind * 2), query(l, r, tm + 1, tr, ind * 2 + 1));
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, q;
cin >> n >>q;
t.resize(4 * n + 1, INT_MAX);
for (int i = 1; i <= q; i++) {
char c;
int a, b;
cin >> c >> a >> b;
if (c == 'M') update(b, a, 1, 1, n);
else {
int l=b, r=n;
bool b = true;
while (l < r) {
int m = (l + r) / 2;
if (query(l, m, 1, n, 1) <= a) r = m;
else if (query(m + 1, r, 1, n, 1) <= a) l = m + 1;
else {
b = false;
break;
}
}
if (query(l, r, 1, n, 1) <= a && b) cout << l << '\n';
else cout << "-1\n";
}
}
}
