using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Collections.Generic;
using System.Diagnostics;
using System.Numerics;
using Enu = System.Linq.Enumerable;

public class Program
{
    Dictionary<long, int> dic = new Dictionary<long, int>();
    static readonly long Mod1 = (long)1e9 + 7, Mod2 = (long)1e9 + 9;
    int N;
    long sum1, sum2;
    long[] C1, C2;

    public void Solve()
    {
        N = Reader.Int();
        int NQ = Reader.Int();
        var Q = Reader.StringTable(NQ);
        Init();
        dic[0] = 0;
        var ans = new List<int>();
        for (int qi = 0; qi < NQ; qi++)
            if (Q[qi][0] == "!") Add(int.Parse(Q[qi][1]), int.Parse(Q[qi][2]), int.Parse(Q[qi][3]), qi + 1);
            else ans.Add(dic[Key()]);
        Console.WriteLine(string.Join("\n", ans));
    }

    void Init()
    {
        var random = new Random();

        long mult = random.Next((int)1e7 + 1, (int)Mod1);
        C1 = new long[N + 1];
        for (long i = 0, m = 1; i < N; i++, m = m * mult % Mod1)
            C1[i + 1] = (C1[i] + m) % Mod1;

        mult = random.Next((int)1e7 + 1, (int)Mod1);
        C2 = new long[N + 1];
        for (long i = 0, m = 1; i < N; i++, m = m * mult % Mod2)
            C2[i + 1] = (C2[i] + m) % Mod2;
    }

    long Key() { return sum1 << 32 | sum2; }

    void Add(int L, int R, int val, int time)
    {
        sum1 = ((sum1 + (C1[R] - C1[L]) * val) % Mod1 + Mod1) % Mod1;
        sum2 = ((sum2 + (C2[R] - C2[L]) * val) % Mod2 + Mod2) % Mod2;
        long key = Key();
        if (!dic.ContainsKey(key)) dic[key] = time;
    }
}


class Entry { static void Main() { new Program().Solve(); } }
class Reader
{
    static TextReader reader = Console.In;
    static readonly char[] separator = { ' ' };
    static readonly StringSplitOptions op = StringSplitOptions.RemoveEmptyEntries;
    static string[] A = new string[0];
    static int i;
    static void Init() { A = new string[0]; }
    public static void Set(TextReader r) { reader = r; Init(); }
    public static void Set(string file) { reader = new StreamReader(file); Init(); }
    public static bool HasNext() { return CheckNext(); }
    public static string String() { return Next(); }
    public static int Int() { return int.Parse(Next()); }
    public static long Long() { return long.Parse(Next()); }
    public static double Double() { return double.Parse(Next()); }
    public static int[] IntLine() { return Array.ConvertAll(Split(Line()), int.Parse); }
    public static int[] IntArray(int N) { return Range(N, Int); }
    public static int[][] IntTable(int H) { return Range(H, IntLine); }
    public static string[] StringArray(int N) { return Range(N, Next); }
    public static string[][] StringTable(int N) { return Range(N, () => Split(Line())); }
    public static string Line() { return reader.ReadLine().Trim(); }
    public static T[] Range<T>(int N, Func<T> f) { var r = new T[N]; for (int i = 0; i < N; r[i++] = f()) ; return r; }
    static string[] Split(string s) { return s.Split(separator, op); }
    static string Next() { CheckNext(); return A[i++]; }
    static bool CheckNext()
    {
        if (i < A.Length) return true;
        string line = reader.ReadLine();
        if (line == null) return false;
        if (line == "") return CheckNext();
        A = Split(line);
        i = 0;
        return true;
    }
}