#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define f1 first
#define s2 second
#define pb push_back
#define mp make_pair
#define ll long long
#define fri(a) freopen(a,"r",stdin);
#define fro(a) freopen(a,"w",stdout);
const int N=1e5+5;
ll n,m,x,y;
pair<int,int>seg[4*N],k;
char c;
void update(int v,int tl,int tr,int pos,int val){
if(tl==tr){
seg[v]={val,tl};
}
else{
int tm=(tl+tr)/2;
if(tm>=pos){
update(v*2,tl,tm,pos,val);
}
else{
update(v*2+1,tm+1,tr,pos,val);
}
seg[v]=min(seg[v*2],seg[v*2+1]);
}
}
pair<int,int> query(int v,int tl,int tr,int l,int r,int val){
if(l<=tl && r>=tr){
return (seg[v].f1)<=val?seg[v]:mp(INT_MAX,-1);
}
if(tr<l || tl>r){
return {INT_MAX,-1};
}
int tm=(tl+tr)/2;
pair<int,int> left=query(v*2,tl,tm,l,r,val);
pair<int,int> right=query(v*2+1,tm+1,tr,l,r,val);
if(left.f1<=val && right.f1<=val){
return left;
}
return min(left,right);
}
int main(){
//fri("in.txt");
//fro("out.txt");
cin>>n>>m;
for(int i=0;i<4*N;i++){
seg[i]={INT_MAX,-1};
}
for(int i=0;i<m;i++){
cin>>c>>x>>y;
if(c=='M'){
update(1,1,n,y,x);
// for(int j=0;j<2*n;j++){
// cout<<seg[j].f1<<"----"<<seg[j].s2<<" ";
// }
// cout<<endl;
}
else{
k=query(1,1,n,y,n,x);
cout<<(k.f1==INT_MAX?-1:k.s2)<<endl;
}
}
return 0;
}
