#include<bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5, INF = 2e9;
int n, m, t[4 * N];
void update(int v, int l, int r, int pos, int val){
if(l == r){
t[v] = val;
return;
}
int mid = (r + l) >> 1;
if(pos <= mid){
update(v + v, l, mid, pos, val);
}
else{
update(v + v + 1, mid + 1, r, pos, val);
}
t[v] = min(t[v + v], t[v + v + 1]);
}
int get(int v, int l, int r, int tl, int tr, int val){
if(l > r || l > tr || tl > r || t[v] > val){
return -1;
}
if(l == r){
return l;
}
int mid = (r + l) >> 1;
int x = get(v + v, l, mid, tl, tr, val);
if(x == -1){
x = get(v + v + 1, mid + 1, r, tl, tr, val);
}
return x;
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin >> n >> m;
for(int i = 1; i <= n; i++){
update(1, 1, n, i, INF);
}
while(m--){
char c;
cin >> c;
if(c == 'M'){
int x, y;
cin >> x >> y;
update(1, 1, n, y, x);
}
else{
int x, y;
cin >> x >> y;
cout << get(1, 1, n, y, n, x) << "\n";
}
}
}
