#include <iostream>
#include <algorithm>
#include <chrono>
#include <random>
#include <unordered_map>
using namespace std;
using i64 = long long;

template <class Int>
vector<Int> segment_sieve(Int a, Int b) {
  Int sqb = sqrt(b);
  vector<bool> is_prime_small(sqb+1, true);
  is_prime_small[0] = is_prime_small[1] = false;
  vector<bool> is_prime(b-a, true);
  is_prime[0] = a != 1;
  for(Int i=2; i*i<b; ++i) {
    if(is_prime_small[i]) {
      for(Int j=2*i; j*j<b; j+=i) { is_prime_small[j] = 0; }
      for(Int j=max(Int(2), (a+i-1)/i)*i; j<b; j+=i) {
        is_prime[j - a] = false;
      }
    }
  }
  vector<Int> res;
  for(Int i=0; i<b-a; ++i) {
    if(is_prime[i]) { res.push_back(i+a); }
  }
  return res;
}

tuple<i64, i64, i64> extgcd(i64 x, i64 y) {
  if(y == 0) { return make_tuple(1, 0, x); }
  i64 a, b, d; tie(a, b, d) = extgcd(y, x%y);
  return make_tuple(b, a-x/y*b, d);
}

i64 mod_inv(i64 a, i64 m) {
  i64 x, y, d; tie(x, y, d) = extgcd(a, m);
  return d==1 ? (x % m + m) % m : -1;
}

i64 calc(const vector<i64> &hs) {
  return (hs[0] << 31) + hs[1];
}

int main(void) {
  cin.tie(0); ios::sync_with_stdio(false);

  i64 N, q; cin >> N >> q;

  unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
  mt19937_64 genrand(seed);
  vector<i64> primes;
  constexpr i64 LO = i64(powl(2, 30)),
                HI = LO + 100000;
  primes = segment_sieve(LO, HI);
  shuffle(begin(primes), end(primes), genrand);
  vector<i64> M(2), B(2), inv(2); // M[2], B[2], inv[2]
  vector<vector<i64>> pw(2, vector<i64>(N+1)); // pw[2][N+1]
  for(int i=0, ptr=0; i<2; ++i) {
    M[i] = primes[ptr++];
    B[i] = primes[ptr++];
    if(M[i] < B[i]) { swap(M[i], B[i]); }
    pw[i][0] = 1;
    for(int j=1; j<=N; ++j) {
      pw[i][j] = pw[i][j-1] * B[i] % M[i];
    }
    inv[i] = mod_inv(B[i]-1, M[i]);
  }

  unordered_map<i64, i64> mp;
  mp[0] = 0;
  vector<i64> hs(2); // hs[2]
  for(i64 qno=0; qno<q; ++qno) {
    char com; cin >> com;
    if(com == '?') {
      cout << mp[calc(hs)] << '\n';
      continue;
    }
    i64 a, b, c; cin >> a >> b >> c;
    for(int i=0; i<2; ++i) {
      i64 v = c;
      v *= pw[i][a]; // mod_pow(B[i], a, M[i]);
      v %= M[i];
      v *= pw[i][b-a] - 1; // mod_pow(B[i], b-a, M[i]) - 1;
      v %= M[i];
      v *= inv[i]; // mod_inv(B[i]-1, M[i]);
      v %= M[i];
      hs[i] += v;
      hs[i] %= M[i];
      if(hs[i] < 0) { hs[i] += M[i]; }
    }
    i64 hash = calc(hs);
    if(!mp.count(hash)) { mp[hash] = qno+1; }
  }
  return 0;
}