#include <bits/stdc++.h>
using namespace std;
#define int long long
int n,q;
const int maxn=200003;
const int INF=LONG_LONG_MAX;
vector <int> a(maxn);
vector <int> t(4*maxn,INF);
void update(int v, int tl, int tr, int pos, int new_val)
{
if(tl==tr)
t[v]=new_val;
else
{
int tm=(tl+tr)/2;
if(tm>=pos)
update(v*2,tl,tm,pos,new_val);
else
update(v*2+1,tm+1,tr,pos,new_val);
t[v]=min(t[v*2],t[v*2+1]);
}
}
int sum(int v, int tl, int tr, int l, int r, int x)
{
if(l>r || t[v]>x)
return -1;
if(tl==tr) return tl;
int tm=(tl+tr)/2;
int left = -1;
if(l <= tm)
left = sum(v*2, tl, tm, l, min(r, tm), x);
if(left != -1) return left;
if(r > tm)
return sum(v*2+1, tm+1, tr, max(l, tm+1), r, x);
return -1;
}
int32_t main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cin>>n>>q;
while(q--)
{
char k;
cin>>k;
if(k=='M')
{
int a,b;
cin>>a>>b;
b--;
update(1,0,n-1,b,a);
}
else
{
int a,b;
cin>>a>>b;
b--;
int ans = sum(1,0,n-1,b,n-1,a);
cout<<(ans==-1 ? -1 : ans+1)<<"\n";
}
}
return 0;
}
