#include <bits/stdc++.h>
using namespace std;
#define nitro ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define int long long
#define vi vector<long long>
#define spc " "
#define yes "YES"
#define no "NO"
#define endl "\n"
const int INF = 1e18;
const int maxn = 200005;
const int mod = 32768;
int tree[4 * maxn];
void build(int node, int start, int end) {
if (start == end) {
tree[node] = INF;
} else {
int mid = (start + end) / 2;
build(2 * node, start, mid);
build(2 * node + 1, mid + 1, end);
tree[node] = min(tree[2 * node], tree[2 * node + 1]);
}
}
void update(int node, int start, int end, int idx, int val) {
if (start == end) {
tree[node] = val;
return;
}
int mid = (start + end) / 2;
if (idx <= mid) update(2 * node, start, mid, idx, val);
else update(2 * node + 1, mid + 1, end, idx, val);
tree[node] = min(tree[2 * node], tree[2 * node + 1]);
}
int query(int node, int start, int end, int b, int y) {
if (tree[node] > y || end < b) return -1;
if (start == end) return start;
int mid = (start + end) / 2;
int res = -1;
if (mid >= b) {
res = query(2 * node, start, mid, b, y);
}
if (res != -1) return res;
return query(2 * node + 1, mid + 1, end, b, y);
}
void solve() {
int n, q;
cin >> n >> q;
build(1, 1, n);
while (q--) {
char type;
int a, b;
cin >> type >> a >> b;
if (type == 'M') {
update(1, 1, n, b, a);
} else {
cout << query(1, 1, n, b, a) << "\n";
}
}
}
signed main() {
nitro
int t = 1;
//cin >> t;
for(int i = 1; i <= t; i++) {
solve();
}
return 0;
}
