#include <bits/stdc++.h>
using namespace std;

#define _p(...) (void)printf(__VA_ARGS__)
#define forr(x,arr) for(auto&& x:arr)
#define _overload3(_1,_2,_3,name,...) name
#define _rep2(i,n) _rep3(i,0,n)
#define _rep3(i,a,b) for(int i=int(a);i<int(b);++i)
#define rep(...) _overload3(__VA_ARGS__,_rep3,_rep2,)(__VA_ARGS__)
#define _rrep2(i,n) _rrep3(i,0,n)
#define _rrep3(i,a,b) for(int i=int(b)-1;i>=int(a);i--)
#define rrep(...) _overload3(__VA_ARGS__,_rrep3,_rrep2,)(__VA_ARGS__)
#define all(x) (x).begin(), (x).end()
#define bit(n) (1LL<<(n))
#define sz(x) ((int)(x).size())
#define fst first
#define snd second
using ll=long long;using pii=pair<int,int>;
using vb=vector<bool>;using vs=vector<string>;
using vi=vector<int>;using vvi=vector<vi>;using vvvi=vector<vvi>;
using vl=vector<ll>;using vvl=vector<vl>;using vvvl=vector<vvl>;
using vd=vector<double>;using vvd=vector<vd>;using vvvd=vector<vvd>;
using vpii=vector<pii>;using vvpii=vector<vpii>;using vvvpii=vector<vvpii>;
template<typename T>T read(){T t;cin>>t;return t;}
template<class T,class U>ostream&operator<<(ostream&o,const pair<T,U>&p){o<<'('<<p.fst<<", "<<p.snd<<')';return o;}

const long long mod = 1000000007;

long long powMod(long long x, long long y) {
  long long r = 1, a = x % mod;
  while (y) {
    if (y & 1) r = (r * a) % mod;
    a = a * a % mod;
    y /= 2;
  }
  return r;
}

long long invMod(long long x) {
  return powMod(x, mod - 2);
}

long long gpSumMod(long long a, long long r, long long n) {
  if (r == 1) return a * n % mod;
  return (a * powMod(r, n) % mod - a + mod) % mod * invMod(r - 1) % mod;
}

void Main() {
  read<int>();
  int Q = read<int>();

  random_device rnd;
  const ll base = (ll)(mod * ((rnd() + 1.0) / bit(32))) % mod;

  map<ll, int> first;

  ll current = 0;
  first[0] = 0;

  rep(q, Q) {
    char t = read<char>();
    if (t == '!') {
      int l = read<int>();
      int r = read<int>();
      int k = read<int>();

      ll sl = gpSumMod(k, base, l);
      ll sr = gpSumMod(-k, base, r);
      current += sl;
      current += sr;
      current %= mod;
      if (first.count(current) == 0) {
        first[current] = q + 1;
      }
    }
    else {
      cout << first[current] << endl;
    }
    //cout << q << " : " << current << endl;
  }
}
int main() { cin.tie(nullptr); ios::sync_with_stdio(false); Main(); return 0; }