#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
using namespace std;

// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
// #pragma GCC target("avx512f,avx512dq,avx512cd,avx512bw,avx512vl")

using ll = long long;
constexpr int INF = 1001001001;
// constexpr int mod = 1000000007;
constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

constexpr int dx[] = {1, 0, -1, 0, 1, 1, -1, -1};
constexpr int dy[] = {0, 1, 0, -1, 1, -1, 1, -1};

template<typename Monoid>
struct SegmentTree{
    using F = function<Monoid(Monoid, Monoid)>;

    int sz;
    vector<Monoid> seg;

    const F f;
    const Monoid M1;

    SegmentTree(const F f, const Monoid& M1) : f(f), M1(M1) {}

    SegmentTree(int n, const F f, const Monoid &M1) : f(f), M1(M1) {
        sz = 1;
        while(sz < n)   sz <<= 1;
        seg.assign(2 * sz, M1);
    }

    void resize(int n){
        sz = 1;
        while(sz < n)   sz <<= 1;
        seg.assign(2 * sz, M1);
    }

    void set(int k, const Monoid &x){
        seg[k + sz] = x;
    }

    void build(){
        for(int k = sz - 1; k > 0; --k){
            seg[k] = f(seg[k << 1], seg[k << 1 | 1]);
        }
    }

    void update(int k, const Monoid &x){
        k += sz;
        seg[k] = x;
        while(k >>= 1){
            seg[k] = f(seg[k << 1], seg[k << 1 | 1]);
        }
    }

    Monoid query(int a, int b){
        Monoid L = M1, R = M1;
        for(a += sz, b += sz; a < b; a >>= 1, b >>= 1){
            if(a & 1)   L = f(L, seg[a++]);
            if(b & 1)   R = f(seg[--b], R);
        }
        return f(L, R);
    }

    Monoid operator[](const int &k) const{
        return seg[k + sz];
    }

    // (type = true) : find_last
    // (type = false) : find_first
    template<typename C>
    int find_subtree(int a, const C &check, Monoid &M, bool type){
        while(a < sz){
            Monoid nxt = type ? f(seg[a << 1 | type], M) : f(M, seg[a << 1 | type]);
            if(check(nxt))  a = a << 1 | type;
            else M = nxt, a = 2 * a + 1 - type;
        }
        return a - sz;
    }

    template<typename C>
    int find_first(int a, const C &check){
        Monoid L = M1;
        if(a <= 0){
            if(check(f(L, seg[1]))) return find_subtree(1, check, L, false);
            return -1;
        }
        int b = sz;
        for(a += sz, b += sz; a < b; a >>= 1, b >>= 1){
            if(a & 1){
                Monoid nxt = f(L, seg[a]);
                if(check(nxt))  return find_subtree(a, check, L, false);
                L = nxt;
                ++a;
            }
        }
        return -1;
    }

    template<typename C>
    int find_last(int b, const C &check){
        Monoid R = M1;
        if(b >= sz){
            if(check(f(seg[1], R))) return find_subtree(1, check, R, true);
            return -1;
        }
        int a = sz;
        for(b += sz; a < b; a >>= 1, b >>= 1){
            if(b & 1){
                Monoid nxt = f(seg[--b], R);
                if(check(nxt))  return find_subtree(b, check, R, true);
                R = nxt;
            }
        }
        return -1;
    }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, Q;
    cin >> N >> Q;
    vector<int> A(N);
    for(int i = 0; i < N; ++i)  cin >> A[i];

    auto f = [](int l, int r) { return l + r; };
    SegmentTree<int> seg(N, f, 0);
    for(int i = 0; i < N; ++i){
        seg.set(i, A[i] == 1);
    }
    seg.build();

    for(int q = 0; q < Q; ++q){
        int T, X, Y;
        cin >> T >> X >> Y;
        --X;
        if(T == 1){
            A[X] = Y;
            seg.update(X, Y == 1);
        }
        else{
            if(Y - X == 1 || A[Y - 1] > 1){
                cout << "F\n";
                continue;
            }
            int l = X - 1, r = Y - 1;
            while(r - l > 1){
                int m = (l + r) / 2;
                (seg.query(m, Y) == Y - m ? r : l) = m;
            }
            cout << (seg.query(r, Y) % 2 == 0 ? "F\n" : "S\n");
        }
    }

    return 0;
}