#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i=0; i<n; i++)
#define pb push_back
typedef long long ll;

struct BIT {
    int size;
    vector<int> node;
    
    BIT(int n) {
        size = n;
        node.resize(n+1);
    }
    
    void add(int i, int x) {
        i++;
        while (i<=size) {
            node[i] += x;
            i += i&(-i);
        }
    }
    
    int acc(int i) {
        int s = 0;
        while (i>0) {
            s += node[i];
            i -= i&(-i);
        }
        return s;
    }
};

int main() {
    cin.tie(0); ios::sync_with_stdio(false);
    
    int N, Q; cin >> N >> Q;
    int A[N]; rep(i, N) cin >> A[i];
    
    BIT bit(N);
    rep(i, N) bit.add(i, A[i]);
    
    while (Q--) {
        int T, X, Y; cin >> T >> X >> Y;
        
        if (T==1) {
            X--;
            bit.add(X, -A[X]);
            A[X] = Y;
            bit.add(X, A[X]);
        } else {
            int l = 0;
            int r = Y-X+1;
            while (l<=r) {
                int m = (l+r)/2;
                int c = bit.acc(Y)-bit.acc(Y-m);
                if (c==m) l = m+1;
                else r = m-1;
            }
            if (r%2==0) cout << "F" << endl;
            else cout << "S" << endl;
        }
    }
}