#include<bits/stdc++.h>

const int inf=2e9+;

const int N=;

using namespace std;

inline int read(){

    int f=,x=;char ch;

    do{ch=getchar();if(ch=='-')f=-;}while(ch<''||ch>'');

    do{x=x*+ch-'';ch=getchar();}while(ch>=''&&ch<='');

    return f*x;

}

int n,m;

struct Segment_Tree_Beats{

#define lson (o<<1)

#define rson (o<<1|1)

    int his[N<<],pra[N<<],prb[N<<],a[N<<],b[N<<],minv[N<<],semn[N<<];

    inline void pushup(int o){

        if(minv[lson]==minv[rson])minv[o]=minv[lson],semn[o]=min(semn[lson],semn[rson]);

        else if(minv[lson]<minv[rson]){minv[o]=minv[lson];semn[o]=min(semn[lson],minv[rson]);}

        else{minv[o]=minv[rson];semn[o]=min(semn[rson],minv[lson]);}

        his[o]=min(his[lson],his[rson]);

    }

    inline void puttag(int o,int v){

        his[o]=min(his[o],minv[o]+v);

        a[o]+=v;b[o]+=v;minv[o]+=v;semn[o]+=v;semn[o]=min(semn[o],inf);

        pra[o]=min(pra[o],a[o]);

        prb[o]=min(prb[o],b[o]);

    }

    inline void plus(int o,int ax,int pa,int bx,int pb){

        his[o]=min(his[o],minv[o]+pa);

        pra[o]=min(pra[o],pa+a[o]);

        prb[o]=min(prb[o],pb+b[o]);

        a[o]+=ax;b[o]+=bx;minv[o]+=ax;semn[o]+=bx;semn[o]=min(semn[o],inf);

    }

    inline void pushdown(int o){

        int mmmm=min(minv[lson],minv[rson]);

        if(minv[lson]==mmmm)plus(lson,a[o],pra[o],b[o],prb[o]);else plus(lson,b[o],prb[o],b[o],prb[o]);

        if(minv[rson]==mmmm)plus(rson,a[o],pra[o],b[o],prb[o]);else plus(rson,b[o],prb[o],b[o],prb[o]);

        a[o]=b[o]=pra[o]=prb[o]=;

    }

    inline void build(int o,int l,int r){

        if(l==r){

            minv[o]=read();his[o]=minv[o];semn[o]=inf;

            return;

        }

        int mid=(l+r)>>;

        build(lson,l,mid);build(rson,mid+,r);

        pushup(o);

    }

    inline void optadd(int o,int l,int r,int ql,int qr,int v){

        if(ql<=l&&r<=qr){puttag(o,v);return;}

        int mid=(l+r)>>;pushdown(o);

        if(ql<=mid)optadd(lson,l,mid,ql,qr,v);

        if(qr>mid)optadd(rson,mid+,r,ql,qr,v);

        pushup(o);

    }

    inline void dfs(int o,int l,int r,int v){

        if(minv[o]>=v)return;

        if(semn[o]>v){

            v-=minv[o];his[o]=min(his[o],minv[o]+v);

            pra[o]=min(pra[o],a[o]+v);

            a[o]+=v;minv[o]+=v;return;

        }

        int mid=(l+r)>>;pushdown(o);

        dfs(lson,l,mid,v);dfs(rson,mid+,r,v);

        pushup(o);

    }

    inline void change(int o,int l,int r,int ql,int qr,int v){

        if(ql<=l&&r<=qr){dfs(o,l,r,v);return;}

        int mid=(l+r)>>;pushdown(o);

        if(ql<=mid)change(lson,l,mid,ql,qr,v);

        if(qr>mid)change(rson,mid+,r,ql,qr,v);

        pushup(o);

    }

    inline int querynow(int o,int l,int r,int ql,int qr){

        if(ql<=l&&r<=qr)return minv[o];

        int mid=(l+r)>>,ans=inf;pushdown(o);

        if(ql<=mid)ans=min(ans,querynow(lson,l,mid,ql,qr));

        if(qr>mid)ans=min(ans,querynow(rson,mid+,r,ql,qr));

        return ans;

    }

    inline int queryhis(int o,int l,int r,int ql,int qr){

        if(ql<=l&&r<=qr)return his[o];

        int mid=(l+r)>>,ans=inf;pushdown(o);

        if(ql<=mid)ans=min(ans,queryhis(lson,l,mid,ql,qr));

        if(qr>mid)ans=min(ans,queryhis(rson,mid+,r,ql,qr));

        return ans;

    }

}T;

int main(){

    n=read();m=read();

    T.build(,,n);

    while(m--){

        int opt=read(),l=read(),r=read();

        if(opt==){int x=read();T.optadd(,,n,l,r,x);}

        if(opt==){int x=read();T.change(,,n,l,r,x);}

        if(opt==)printf("%d\n",T.querynow(,,n,l,r));

        if(opt==)printf("%d\n",T.queryhis(,,n,l,r));

    }

}