#include <string>
#include <vector>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<stack>
#include<queue>
#include<cmath>
#include<algorithm>
#include<functional>
#include<list>
#include<deque>
#include<bitset>
#include<set>
#include<map>
#include<unordered_map>
#include<unordered_set>
#include<cstring>
#include<sstream>
#include<complex>
#include<iomanip>
#include<numeric>
#include<cassert>
#define X first
#define Y second
#define pb push_back
#define rep(X,Y) for (int (X) = 0;(X) < (Y);++(X))
#define reps(X,S,Y) for (int (X) = S;(X) < (Y);++(X))
#define rrep(X,Y) for (int (X) = (Y)-1;(X) >=0;--(X))
#define rreps(X,S,Y) for (int (X) = (Y)-1;(X) >= (S);--(X))
#define repe(X,Y) for ((X) = 0;(X) < (Y);++(X))
#define peat(X,Y) for (;(X) < (Y);++(X))
#define all(X) (X).begin(),(X).end()
#define rall(X) (X).rbegin(),(X).rend()
#define eb emplace_back
#define UNIQUE(X) (X).erase(unique(all(X)),(X).end())
#define Endl endl
#define NL <<"\n"

using namespace std;
using ll=long long;
using pii=pair<int,int>;
using pll=pair<ll,ll>;
template<class T> using vv=vector<vector<T>>;
template<class T> inline bool MX(T &l,const T &r){return l<r?l=r,1:0;}
template<class T> inline bool MN(T &l,const T &r){return l>r?l=r,1:0;}
//#undef NUIP
#ifdef NUIP
#include "benri.h"
#else
#define out(args...)
#endif
#ifdef __cpp_init_captures
template<typename T>vector<T> table(int n, T v){ return vector<T>(n, v);}
template <class... Args> auto table(int n, Args... args){auto val = table(args...); return vector<decltype(val)>(n, move(val));}
#endif
const ll MOD=1e9+7; //998244353

const int N=(1<<17);

template<class T>
struct Seg{
	T s;
	Seg (T s=0):s(s){}
	Seg operator+(const Seg &seg){
		return s+seg.s;
	}
  static Seg e;
};
template<class T> Seg<T> Seg<T>::e=Seg();

template<class T>
struct Lfun{
	T a,b;
  Lfun(T a=1,T b=0):a(a),b(b){}
	void operator+=(const Lfun &lfun){
		a*=lfun.a;
		(b*=lfun.a)+=lfun.b;
	}
	bool operator==(const Lfun &lfun){ return a==lfun.a && b==lfun.b;}

	void eval(Seg<T> &s,int l,int r){
		(s.s*=a)+=b*(r-l);
	}
	static Lfun e;
};
template<class T> Lfun<T> Lfun<T>::e=Lfun();

template<class Seg, class Ope>
struct SegTree{
	vector<Seg> segs;
	vector<Ope> opes;
	
	void lazy_eval(int k,int a,int b){
		if(opes[k]==Ope::e) return;
		opes[k].eval(segs[k],a,b);
		if(2*k+2<opes.size()){
			opes[2*k+1]+=opes[k];
			opes[2*k+2]+=opes[k];
		}
		opes[k]=Ope::e;
	}
	void upd_node(int k){segs[k]=segs[2*k+1]+segs[2*k+2];}
	void upd(int l,int r,Ope ope,int k,int a,int b){
		lazy_eval(k,a,b);
		if(b<=l || r<=a) return; 
		if(l<=a && b<=r){
			opes[k]+=ope;
			lazy_eval(k,a,b);
			return;
		}	
		int m=(a+b)/2;
		upd(l,r,ope,2*k+1,a,m);
		upd(l,r,ope,2*k+2,m,b);
		upd_node(k);
	}

	Seg query(int l,int r,int k,int a,int b){
		lazy_eval(k,a,b);
		if(b<=l || r<=a)return Seg::e; 
		if(l<=a && b<=r){return segs[k];}
  
		int m=(a+b)/2;
		Seg vl=query(l,r,2*k+1,a,m);
		Seg vr=query(l,r,2*k+2,m,b);
		upd_node(k);
		return vl+vr;
	}

	SegTree(int n){
		int pw=1;
		while(pw<n) pw*=2;
		segs.resize(2*pw);
		opes.resize(2*pw);
	}
	void operator()(int l,int r,Ope ope){ upd(l,r,ope,0,0,segs.size()/2);};
	Seg operator()(int l,int r){ return query(l,r,0,0,segs.size()/2);};
};

int main(){
  ios_base::sync_with_stdio(false); cin.tie(0);
  cout<<fixed<<setprecision(0);
	int n,q;
	cin>>n>>q;
	SegTree<Seg<ll>,Lfun<ll>> st(n);
	rep(i,q){
		int t;
		cin>>t;
		if(t){
			int s,t;
			cin>>s>>t; ++t;
			cout<<st(s,t).s NL;
		}else{
			int s,t,x;
			cin>>s>>t>>x; ++t;
			st(s,t,{0,x});
		}
	}
  return 0;
}



Measured memory_bytes: 8908