#include <bits/stdc++.h>
#include<unordered_map>
using namespace std;
#define ll long long
#define endl "\n"
#define Sara ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
const long long mod=998244353;
const double PI=acos(-1);
int main()
{
//freopen("input.in","r",stdin);
Sara
ll n,q;
cin>>n>>q;
map<ll,ll>stops;
vector<ll>v(n+1);
while(q--){
char o;
cin>>o;
if(o=='M'){
ll x,c;
cin>>x>>c;
stops[c]=x;
}
else{
ll y,b;
cin>>y>>b;
bool ok=0;
for(int i=b;i<=n;i++){
if(stops[i]<=y && stops[i]>0){
cout<<i<<endl;
ok=1;
break;
}
}
if(!ok) cout<<-1<<endl;
}
}
return 0;
}
