#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define gcd __gcd
#define sz(v) (int) v.size()
#define pb push_back
#define pi pair<int,int>
#define all(v) (v).begin(), (v).end()
#define compact(v) (v).erase(unique(all(v)), (v).end())
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define REV(i, a, b) for(int i = (a); i >= (b); i--)
#define dbg(x) "[" #x " = " << (x) << "]"
///#define int long long
using ll = long long;
using ld = long double;
using ull = unsigned long long;
template<typename T> bool ckmx(T& a, const T& b){if(a < b) return a = b, true; return false;}
template<typename T> bool ckmn(T& a, const T& b){if(a > b) return a = b, true; return false;}
const int N = 2e5+5;
const ll MOD = 1e9+7;
const ll INF = 1e18;
struct SMT{
int trsz;
vector<int> st;
SMT(int n = 0): trsz(n), st((n << 2) | 1, 1e9 + 7) {}
void update(int id, int l, int r, int x, int val){
if(l == r){
st[id] = val;
}
else{
int m = l+r>>1;
if(x <= m)
update(id << 1, l, m, x, val);
else update(id << 1|1, m+1, r, x, val);
st[id] = min(st[id << 1], st[id << 1|1]);
}
}
int query(int id, int l, int r, int u, int v){
if(l > v || r < u) return 1e9 + 7;
if(l >= u && r <= v) return st[id];
int m = l+r>>1;
return min(query(id << 1, l, m, u, v), query(id << 1|1, m+1, r, u, v));
}
int query(int l, int r){
return query(1, 1, trsz, l, r);
}
void update(int x, int val){
update(1, 1, trsz, x, val);
}
};
void solve()
{
int n,q; cin >> n >> q;
SMT st(n);
auto find_answer = [&](int start, int target) -> int{
int l = start - 1, r = n + 1;
while(l + 1 < r){
int m = l+r>>1;
if(st.query(start, m) <= target){
r = m;
}
else l = m;
}
return (r == n + 1 ? -1 : r);
};
while(q--){
char op; cin >> op;
if(op == 'M'){
int x,a; cin >> x >> a;
st.update(a, x);
}
else{
int y,b; cin >> y >> b;
cout << find_answer(b, y) << "\n";
}
}
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
#define name "InvMOD"
if(fopen(name".INP", "r")){
freopen(name".INP","r",stdin);
freopen(name".OUT","w",stdout);
}
int t = 1; //cin >> t;
while(t--) solve();
return 0;
}
