#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
#define fix(x) fixed << setprecision(x)
#define asc(x) x, vector<x>, greater<x>
#define rep(i, n) for(ll i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
template <typename T>
struct BIT{
    int n;
    vector<T> data;
    BIT(int n=0) : n(n), data(n+1){}
    T sum(int i){
        T res = 0;
        for(; i; i -= i&-i){
            res += data[i];
        }
        return res;
    }
    void add(int i, T x){
        for(; i <= n; i += i&-i){
            data[i] += x;
        }
    }
};

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n,q;
    cin >> n >> q;
    vector<int> a(n);
    BIT<int> bit(n);
    rep(i,n){
        cin >> a[i];
        if(a[i]>1) bit.add(i+1, 1);
    }
    rep(i,q){
        int t,x,y;
        cin >> t >> x >> y;
        if(t==1){
            bit.add(x, (y>1)-(a[x]>1));
            a[x-1] = y;
        }else{
            int ok = x-1, ng = y+1;
            while(ng-ok>1){
                int md = (ok+ng)/2;
                if(bit.sum(y)==bit.sum(md)) ng = md;
                else ok = md;
            }
            cout << (((y-ok)&1)?"F\n":"S\n");
        }
    }
    return 0;
}