#include "bits/stdc++.h"
using namespace std;
#ifdef duc_debug
#include "bits/debug.h"
#else
#define debug(...)
#endif
const int maxn = 2e5 + 5;
int n, q;
map<int, int> bit[maxn];
void update(int x, int val) {
for(int i = x; i > 0; i -= i & (-i)) {
auto it = bit[i].lower_bound(val);
while(it != bit[i].end()) {
if(it->second > x) {
it = bit[i].erase(it);
} else break;
}
bit[i].insert(make_pair(val, x));
}
}
int get(int i, int val) {
int res = 2e9;
for(; i <= n; i += i & (-i)) {
auto it = bit[i].upper_bound(val);
if(it != bit[i].begin()) {
it--;
res = min(res, it->second);
}
}
return res;
}
void solve() {
cin >> n >> q;
while(q--) {
char op; cin >> op;
if(op == 'M') {
int x, a; cin >> x >> a;
update(a, x);
} else {
int y, b; cin >> y >> b;
int res = get(b, y);
cout << (res > 1e9 ? -1 : res) << '\n';
}
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
solve();
return 0;
}
