#include <bits/stdc++.h>
using namespace std;
const int maxn = 200005;
int t[maxn];
int fa[maxn*8];
int n, q;
void epit(int hol, int tol, int ig) {
if(tol == ig) {
fa[hol] = tol;
return;
}
int mid = (tol + ig) / 2;
epit(hol*2,tol,mid);
epit(hol*2+1,mid+1,ig);
fa[hol] = (t[fa[hol*2]] < t[fa[hol*2+1]] ? fa[hol*2] : fa[hol*2+1]);
return;
}
void allit(int hol, int tol, int ig, int cel, int x) {
if(tol == ig) {
t[tol] = x;
return;
}
int mid = (tol + ig) / 2;
if(cel <= mid) allit(hol*2,tol,mid,cel,x);
else allit(hol*2+1,mid+1,ig,cel,x);
fa[hol] = (t[fa[hol*2]] < t[fa[hol*2+1]] ? fa[hol*2] : fa[hol*2+1]);
return;
}
int kiaz(int hol, int tol, int ig, int idos, int y) {
if(tol == ig) {
return (idos <= tol && t[tol] <= y ? tol : -2);
}
if(ig < idos) {
return -2;
}
if(tol <= idos && idos <= ig) {
int mid = (tol + ig) / 2;
int res = kiaz(hol*2,tol,mid,idos,y);
if(res != -2) return res;
if(t[fa[hol*2 + 1]] > y) return -2;
return kiaz(hol*2+1,mid+1,ig,idos,y);
}
int mid = (tol + ig) / 2;
if(t[fa[hol*2]] <= y) {
return kiaz(hol*2,tol,mid,idos,y);
}
if(t[fa[hol*2 + 1]] > y) return -2;
return kiaz(hol*2+1,mid+1,ig,idos,y);
}
void setup() {
for(int i=0;i<n;i++) {
t[i] = INT_MAX;
}
epit(1,0,n-1);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin>>n>>q;
setup();
vector<int> sol;
for(int i=0;i<q;i++) {
char ez;
cin>>ez;
if(ez == 'M') {
int x, a;
cin>>x>>a;
allit(1,0,n-1,a-1,x);
}
else {
int y, b;
cin>>y>>b;
sol.push_back(kiaz(1,0,n-1,b-1,y) + 1);
}
}
for(int d:sol) {
cout<<d<<endl;
}
return 0;
}
