#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define str string
#define pb push_back
#define pf push_front
#define in insert
#define all(v) v.begin(),v.end()
#define fastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
const int sz=1000000,INF=1000000000;
using namespace std;
vector<ll>mins;
ll getMin(ll left,ll right,ll index,ll Left,ll Right)
{
if(left>Right || right<Left)
{
return INF;
}
if(left>=Left && right<=Right)
{
return mins[index];
}
else
{
ll middle=(left+right)/2;
return min(getMin(left,middle,2*index,Left,Right),getMin(middle+1,right,2*index+1,Left,Right));
}
}
void update(ll left,ll right,ll index,ll Index,ll Num)
{
if(Index>=left && Index<=right)
{
if(left==right)
{
mins[index]=Num;
}
else
{
ll middle=(left+right)/2;
if(Index<=middle)
{
update(left,middle,2*index,Index,Num);
}
else
{
update(middle+1,right,2*index+1,Index,Num);
}
mins[index]=min(mins[2*index],mins[2*index+1]);
}
}
}
void solve()
{
ll n,m,num1,num2,left,right,middle,ans;
char c;
cin>>n>>m;
mins.resize(4*n+1),fill(all(mins),INF);
for(int i=0;i<m;i++)
{
cin>>c>>num1>>num2;
if(c=='D')
{
left=num2,right=n,ans=-1;
while(left<=right)
{
middle=(left+right)/2;
if(getMin(1,n,1,num2,middle)>num1)
{
left=middle+1;
}
else
{
right=middle-1,ans=middle;
}
}
cout<<ans<<"\n";
}
else
{
update(1,n,1,num2,num1);
}
}
}
int main()
{
fastIO;
ll t=1;
//cin>>t;
while(t--)
{
solve();
}
}
