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

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

using ll=long long;
#define int ll

//not a multiset
//find_by_order(k) -> itr of k-th(0-based) element
//order_of_key(k) -> index of lower_bound(k)
using ordered_set=tree<
int,
null_type,
less<int>,
rb_tree_tag,
tree_order_statistics_node_update>;

#define rng(i,a,b) for(int i=int(a);i<int(b);i++)
#define rep(i,b) rng(i,0,b)
#define gnr(i,a,b) for(int i=int(b)-1;i>=int(a);i--)
#define per(i,b) gnr(i,0,b)
#define pb push_back
#define eb emplace_back
#define a first
#define b second
#define bg begin()
#define ed end()
#define all(x) x.bg,x.ed
#ifdef LOCAL
#define dmp(x) cerr<<__LINE__<<" "<<#x<<" "<<x<<endl
#else
#define dmp(x) void(0)
#endif

template<class t,class u> void chmax(t&a,u b){if(a<b)a=b;}
template<class t,class u> void chmin(t&a,u b){if(b<a)a=b;}

template<class t> using vc=vector<t>;
template<class t> using vvc=vc<vc<t>>;

using pi=pair<int,int>;
using vi=vc<int>;

template<class t,class u>
ostream& operator<<(ostream& os,const pair<t,u>& p){
	return os<<"{"<<p.a<<","<<p.b<<"}";
}

template<class t> ostream& operator<<(ostream& os,const vc<t>& v){
	os<<"{";
	for(auto e:v)os<<e<<",";
	return os<<"}";
}

#define mp make_pair
#define mt make_tuple
#define one(x) memset(x,-1,sizeof(x))
#define zero(x) memset(x,0,sizeof(x))
#ifdef LOCAL
void dmpr(ostream&os){os<<endl;}
template<class T,class... Args>
void dmpr(ostream&os,const T&t,const Args&... args){
	os<<t<<" ";
	dmpr(os,args...);
}
#define dmp2(...) dmpr(cerr,"Line:",__LINE__,##__VA_ARGS__)
#else
#define dmp2(...) void(0)
#endif

using uint=unsigned;
using ull=unsigned long long;

template<class t,size_t n>
ostream& operator<<(ostream&os,const array<t,n>&a){
	return os<<vc<t>(all(a));
}

template<int i,class T>
void print_tuple(ostream&,const T&){
}

template<int i,class T,class H,class ...Args>
void print_tuple(ostream&os,const T&t){
	if(i)os<<",";
	os<<get<i>(t);
	print_tuple<i+1,T,Args...>(os,t);
}

template<class ...Args>
ostream& operator<<(ostream&os,const tuple<Args...>&t){
	os<<"{";
	print_tuple<0,tuple<Args...>,Args...>(os,t);
	return os<<"}";
}

void print(ll x,int suc=1){
	cout<<x;
	if(suc==1)
		cout<<"\n";
	if(suc==2)
		cout<<" ";
}

ll read(){
	ll i;
	cin>>i;
	return i;
}

vi readvi(int n,int off=0){
	vi v(n);
	rep(i,n)v[i]=read()+off;
	return v;
}

template<class T>
void print(const vector<T>&v,int suc=1){
	rep(i,v.size())
		print(v[i],i==int(v.size())-1?suc:2);
}

string readString(){
	string s;
	cin>>s;
	return s;
}

template<class T>
T sq(const T& t){
	return t*t;
}

//#define CAPITAL
void yes(bool ex=true){
	#ifdef CAPITAL
	cout<<"YES"<<endl;
	#else
	cout<<"Yes"<<endl;
	#endif
	if(ex)exit(0);
}
void no(bool ex=true){
	#ifdef CAPITAL
	cout<<"NO"<<endl;
	#else
	cout<<"No"<<endl;
	#endif
	if(ex)exit(0);
}
void possible(bool ex=true){
	#ifdef CAPITAL
	cout<<"POSSIBLE"<<endl;
	#else
	cout<<"Possible"<<endl;
	#endif
	if(ex)exit(0);
}
void impossible(bool ex=true){
	#ifdef CAPITAL
	cout<<"IMPOSSIBLE"<<endl;
	#else
	cout<<"Impossible"<<endl;
	#endif
	if(ex)exit(0);
}

constexpr ll ten(int n){
	return n==0?1:ten(n-1)*10;
}

const ll infLL=LLONG_MAX/3;

#ifdef int
const int inf=infLL;
#else
const int inf=INT_MAX/2-100;
#endif

int topbit(signed t){
	return t==0?-1:31-__builtin_clz(t);
}
int topbit(ll t){
	return t==0?-1:63-__builtin_clzll(t);
}
int botbit(signed a){
	return a==0?32:__builtin_ctz(a);
}
int botbit(ll a){
	return a==0?64:__builtin_ctzll(a);
}
int popcount(signed t){
	return __builtin_popcount(t);
}
int popcount(ll t){
	return __builtin_popcountll(t);
}
bool ispow2(int i){
	return i&&(i&-i)==i;
}
int mask(int i){
	return (int(1)<<i)-1;
}

bool inc(int a,int b,int c){
	return a<=b&&b<=c;
}

template<class t> void mkuni(vc<t>&v){
	sort(all(v));
	v.erase(unique(all(v)),v.ed);
}

ll rand_int(ll l, ll r) { //[l, r]
	#ifdef LOCAL
	static mt19937_64 gen;
	#else
    static random_device rd;
    static mt19937_64 gen(rd());
    #endif
    return uniform_int_distribution<ll>(l, r)(gen);
}

template<class t>
int lwb(const vc<t>&v,const t&a){
	return lower_bound(all(v),a)-v.bg;
}

template<class t>
struct BIT{
	vc<t> buf;
	int s;
	BIT(int n=0){init(n);}
	void init(int n){buf.assign(s=n,0);}
	void add(int i,t v){
		for(;i<s;i+=(i+1)&(-i-1))
			buf[i]+=v;
	}
	t get(int i){
		t res=0;
		for(;i>=0;i-=(i+1)&(-i-1))
			res+=buf[i];
		return res;
	}
	t sum(int b,int e){
		return get(e-1)-get(b-1);
	}
	/*int kth(int k){
		int res=0;
		for(int i=topbit(s);i>=0;i--){
			int w=res+(1<<i);
			if(w<=s&&buf[w-1]<=k){
				k-=buf[w-1];
				res=w;
			}
		}
		return res;
	}*/
};

struct query{
	int l,r,x;
};

const int nmax=100010;
int a[nmax],b[nmax];

pi buf[nmax];
int waf[nmax],relka[nmax];

struct ysp{
	int x,l,r;
	int s=0;
	void init(int l_,int rr){
		x=0;
		l=l_;
		r=rr;
		rng(i,l,r)
			buf[i]=pi(b[i]-a[i],b[i]);
		sort(buf+l,buf+r);
		{
			int cur=inf;
			rng(i,l,r){
				chmin(cur,buf[i].b-buf[i].a);
				waf[i]=cur;
			}
		}
		{
			int cur=inf;
			gnr(i,l,r){
				chmin(cur,buf[i].b);
				relka[i]=cur;
			}
		}
	}
	void add(int v){
		x+=v;
	}
	void done(){
		rng(i,l,r)
			a[i]+=x;
	}
	int getans(){
		int i=lower_bound(buf+l,buf+r,pi(x,0))-buf;
		int ans=inf;
		if(l<i)chmin(ans,waf[i-1]+x);
		//dmp2(i,l,r);
		//dmp(vc<pi>(buf+l,buf+r));
		//dmp(ans);
		if(i<r)chmin(ans,relka[i]);
		return ans;
	}
};

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(0);
	cout<<fixed<<setprecision(20);
	
	int n;cin>>n;
	int q;cin>>q;
	
	rep(i,n)
		cin>>a[i]>>b[i];
	
	const int B=250;
	
	for(int i=0;i<q;i+=B){
		vc<query> qs;
		vi ps{0,n};
		for(int j=i;j<min(i+B,n);j++){
			int t,l,r;cin>>t>>l>>r;
			l--;
			if(t==1){
				int x;cin>>x;
				qs.pb({l,r,x});
			}else{
				qs.pb({l,r,-1});
			}
			ps.pb(l);
			ps.pb(r);
		}
		mkuni(ps);
		int s=ps.size()-1;
		vc<ysp> ys(s);
		rep(j,s)
			ys[j].init(ps[j],ps[j+1]);
		for(auto z:qs){
			int l=lwb(ps,z.l);
			int r=lwb(ps,z.r);
			if(z.x==-1){
				int ans=inf;
				rng(j,l,r)
					chmin(ans,ys[j].getans());
				print(ans);
			}else{
				rng(j,l,r)
					ys[j].add(z.x);
			}
		}
		rep(j,s)
			ys[j].done();
	}
}



Measured memory_bytes: 7948