#include <iostream>
#include <vector>
#include <map>
#include <random>

using namespace std;

typedef long long ll;

const ll MOD_A = 1000000000000000003LL; // Large prime for modulo operation
const ll MOD_B = 1000000000000000031LL; // Another large prime

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

    int N, Q;
    cin >> N >> Q;

    // Generate random coefficients a and b for each element
    vector<ll> a(N), b(N);
    random_device rd;
    mt19937_64 gen(rd());
    uniform_int_distribution<ll> dis_a(1, MOD_A - 1);
    uniform_int_distribution<ll> dis_b(1, MOD_B - 1);

    for (int i = 0; i < N; ++i) {
        a[i] = dis_a(gen);
        b[i] = dis_b(gen);
    }

    // Compute prefix sums for a and b
    vector<ll> prefix_a(N + 1, 0), prefix_b(N + 1, 0);
    for (int i = 0; i < N; ++i) {
        prefix_a[i + 1] = prefix_a[i] + a[i];
        prefix_b[i + 1] = prefix_b[i] + b[i];
    }

    // Current hash values
    ll current_hash_a = 0, current_hash_b = 0;
    map<pair<ll, ll>, int> hash_map;
    hash_map[{0, 0}] = 0; // Initial state after 0 queries

    for (int q = 1; q <= Q; ++q) {
        string type;
        cin >> type;

        if (type == "!") {
            int L, R, K;
            cin >> L >> R >> K;

            // Calculate sum_a and sum_b for the interval [L, R)
            ll sum_a = prefix_a[R] - prefix_a[L];
            ll sum_b = prefix_b[R] - prefix_b[L];

            // Apply modulo to handle negative values
            ll sum_a_mod = (sum_a % MOD_A + MOD_A) % MOD_A;
            ll sum_b_mod = (sum_b % MOD_B + MOD_B) % MOD_B;

            ll delta_a = (sum_a_mod * K) % MOD_A;
            current_hash_a = (current_hash_a + delta_a) % MOD_A;

            ll delta_b = (sum_b_mod * K) % MOD_B;
            current_hash_b = (current_hash_b + delta_b) % MOD_B;

            // Ensure non-negative
            current_hash_a = (current_hash_a + MOD_A) % MOD_A;
            current_hash_b = (current_hash_b + MOD_B) % MOD_B;

            pair<ll, ll> current_hash = {current_hash_a, current_hash_b};
            if (hash_map.find(current_hash) == hash_map.end()) {
                hash_map[current_hash] = q;
            }
        } else if (type == "?") {
            pair<ll, ll> current_hash = {current_hash_a, current_hash_b};
            auto it = hash_map.find(current_hash);
            if (it != hash_map.end()) {
                cout << it->second << '\n';
            } else {
                // This case should not occur as per the problem constraints
                cout << 0 << '\n';
            }
        }
    }

    return 0;
}