#include "bits/stdc++.h"
#define Rep(i,n) for(int i=0;i<(int)(n);i++)
#define For(i,n1,n2) for(int i=(int)(n1);i<(int)(n2);i++)
#define REP(i,n) for(ll i=0;i<(ll)(n);i++)
#define RREP(i,n) for(ll i=((ll)(n)-1);i>=0;i--)
#define FOR(i,n1,n2) for(ll i=(ll)(n1);i<(ll)(n2);i++)
#define RFOR(i,n1,n2) for(ll i=((ll)(n1)-1);i>=(ll)(n2);i--)
#define all(a)  (a).begin(),(a).end()
#define IOS std::cin.tie(0),std::ios::sync_with_stdio(false)

namespace idaten {

	using namespace std;
	using ll = int_fast64_t;
	using ull = uint_fast64_t;
	using P = std::pair<int64_t, int64_t>;
	template<typename T1, typename T2> inline bool chmin(T1& a, T2 b) { if (a > b) { a = b; return 1; }return 0; }
	template<typename T1, typename T2> inline bool chmax(T1& a, T2 b) { if (a < b) { a = b; return 1; }return 0; }
	template<class Type>struct is_vector : std::false_type {};
	template<class ValueType, class Alloc>struct is_vector<std::vector<ValueType, Alloc>> : std::true_type {};
	template <typename T> inline std::ostream& operator << (std::ostream& out, const std::vector<T>& v) {
		if (v.empty())return out;
		constexpr bool is_vector_v = is_vector<T>::value;
		if (is_vector_v)for (auto itr = v.begin(); itr != v.end();)out << (*itr), out << ((++itr != v.end()) ? "\n" : "");
		else for (auto itr = v.begin(); itr != v.end();)out << (*itr), out << ((++itr != v.end()) ? " " : "");
		return out;
	}
	inline void put() {}
	template<class T> inline void put(const T& first) { std::cout << first << "\n"; }
	template<class T, class... N> inline void put(const T& first, const N& ... rest) { std::cout << first << " "; put(rest...); }
	inline void putn() {}
	template<class T, class... N> inline void putn(const T& first, const N& ... rest) { std::cout << first << "\n"; putn(rest...); }
	//*
	template<typename F,typename T>
	class Monoid {
	public:
		const T unit; // 単位元
		const F f; // 関数
		const int flag;
		Monoid(F f, T unit, int flag = 0) : f(f), unit(unit), flag(flag) {}
	};

	template<typename Up, typename Proc>
	class LazySegmentTree {
	public:
		int sz = 1;
		const Up up;		// 更新関数
		const Proc proc;	// 取得関数
		using T = remove_const_t<decltype(up.unit)>; // up関数の型
		vector<T> seg; // セグメント木のデータ配列
		vector<T> lazy; // 遅延評価用の配列
		LazySegmentTree(int n, Up up, Proc proc) : up(up), proc(proc) {
			while (sz < n) sz <<= 1;
			seg.clear();
			lazy.clear();
			seg.resize(sz * 2, proc.unit);
			lazy.resize(sz * 2, up.unit);
		}
		T cont(T& a, int b) { // aをb回procした値
			if (b <= 0)return proc.unit;
			if (b % 2 == 0) {
				T c = cont(a, b / 2);
				return proc.f(c, c);
			} else {
				return proc.f(a, cont(a, b - 1));
			}
			return a;
		}
		T contSum(T& a, int b) { // procが加算のとき
			return a * b;
		}
		T contId(T& a, int b) { // procが繰り返しても同じ値になるもの(max,min,etc...)
			return a;
		}
		void init(std::vector<T> ary) { // aryで初期化する
			const int n = (int)ary.size();
			for (int i = 0; i < n; ++i) {
				set(i, ary[i]);
			}
			for (int i = sz - 2; i >= 0; --i) {
				seg[i] = proc.f(seg[2 * i + 1], seg[2 * i + 2]);
			}
		}
		void init(T a) { // sz個の全要素をaで初期化する
			for (int i = 0; i < sz; ++i) {
				set(i, a);
			}
			for (int i = sz - 2; i >= 0; --i) {
				seg[i] = proc.f(seg[2 * i + 1], seg[2 * i + 2]);
			}
		}
		inline void set(const int& k, const T& x) {// 左からk番目の葉にxを代入する
			seg[sz - 1 + k] = x;
		}

		// k 番目のノードについて遅延評価を行う
		void eval(int k, int l, int r) { // k = [l,r)
			if (lazy[k] != up.unit) {
				int len = r - l;
				if (len > 1) {
					lazy[2 * k + 1] = up.f(lazy[2 * k + 1], lazy[k]);
					lazy[2 * k + 2] = up.f(lazy[2 * k + 2], lazy[k]);
				}
				if (proc.flag == 0) {
					seg[k] = up.f(seg[k], cont(lazy[k], len));
				} else if (proc.flag == 1) {
					seg[k] = up.f(seg[k], contSum(lazy[k], len));
				} else if (proc.flag == 2) {
					seg[k] = up.f(seg[k], contId(lazy[k], len));
				}
				lazy[k] = up.unit;
			}
		}
		void update(int a, int b, T x, int k = 0, int l = 0, int r = -1) { // i in [a,b)に更新up(seg[i],a)を適用
			if (r < 0) r = sz;
			eval(k, l, r);
			if (b <= l || r <= a) return;
			if (a <= l && r <= b) {// 被覆
				lazy[k] = up.f(lazy[k], x);
				eval(k, l, r);
			} else {// 非被覆
				update(a, b, x, 2 * k + 1, l, (l + r) / 2);
				update(a, b, x, 2 * k + 2, (l + r) / 2, r);
				seg[k] = proc.f(seg[2 * k + 1], seg[2 * k + 2]);
			}
		}
		T query(int a, int b, int k = 0, int l = 0, int r = -1) {
			if (r < 0) r = sz;
			if (b <= l || r <= a) return proc.unit;
			eval(k, l, r);
			if (a <= l && r <= b) return seg[k];
			T vl = query(a, b, 2 * k + 1, l, (l + r) / 2);
			T vr = query(a, b, 2 * k + 2, (l + r) / 2, r);
			return proc.f(vl, vr);
		}
	};

	
	void solve() {
		using type = int64_t;
		auto assign_lambda = [](type& a, type b) {
			return b;
		};
		constexpr type assignUnit = std::numeric_limits<type>::min();
		Monoid<decltype(assign_lambda),decltype(assignUnit)> assign(assign_lambda, assignUnit, 2);
		//Monoid assign(assign_lambda, assignUnit, 2);

		auto sum_lambda = [](type& a, type b) {
			return a + b;
		};
		constexpr type sumUnit = 0;
		Monoid<decltype(sum_lambda), decltype(sumUnit)> sum(sum_lambda, sumUnit, 1);
		//Monoid sum(sum_lambda, sumUnit, 1);

		auto min_lambda = [](type& a, type b) {
			if (a < b)return a;
			return b;
		};
		constexpr type minUnit = numeric_limits<type>::max();
		Monoid<decltype(min_lambda), decltype(minUnit)> intmin(min_lambda, minUnit, 2);
		//Monoid intmin(min_lambda, minUnit, 2);

		auto max_lambda = [](type& a, type b) {
			if (a > b)return a;
			return b;
		};
		constexpr type maxUnit = std::numeric_limits<type>::min();
		Monoid<decltype(max_lambda), decltype(maxUnit)> intmax(max_lambda, maxUnit, 2);
		//Monoid intmax(max_lambda, maxUnit, 2);

		int n, q;
		cin >> n >> q;
		LazySegmentTree<decltype(assign), decltype(sum)> lst(n, assign, sum);
		lst.init(0);
		//LazySegmentTree lst(n, assignt, intmin);
		REP(i, q) {
			int a;
			cin >> a;
			if (a) {
				int s, t;
				cin >> s >> t;
				//s--, t--;
				put(lst.query(s, t + 1));
			} else {
				int s, t, x;
				cin >> s >> t >> x;
				//s--, t--;
				lst.update(s, t + 1, x);
			}

		}
	}
} // namespace idaten

int main() {
	idaten::solve();
	return 0;
}



Measured memory_bytes: 7020