#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
#define pb push_back
const int N = 200'100;
constexpr int base = 1 << 20;
LL tree[2*base];
void build(int v, int a, int b)
{
if(a==b)
tree[v] = LLONG_MAX;
else
{
int mid = (a+b)/2;
build(v*2, a, mid);
build(v*2+1, mid+1, b);
tree[v] = LLONG_MAX;
}
}
void update(int v, int a, int b, int pos, int val)
{
if(a==b)
tree[v] = val;
else
{
int mid = (a+b)/2;
if(pos <= mid) update(v*2, a, mid, pos, val);
else update(v*2+1, mid+1, b, pos, val);
tree[v] = min(tree[v*2], tree[v*2+1]);
}
}
int p, k, val;
int get_first(int v, int a, int b)
{
// cout << v << " " << a << " " << b << " : " << tree[v] << endl;
if(a > k || b < p)
return -1;
if(tree[v] > val || tree[v] == LLONG_MAX)
return -1;
if(a==b)
return a;
int mid = (a+b)/2;
int left = get_first(2*v, a, mid);
if(left != -1) return left;
return get_first(2*v+1, mid+1, b);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n, m;
cin >> n >> m;
build(1, 1, base-1);
while(m--)
{
char t; int a, b;
cin >> t >> a >> b;
if(t == 'M')
{
update(1, 1, base-1, b, a);
}
else
{
p = b, k = n, val = a;
cout << get_first(1, 1, base-1) << "\n";
}
}
}
