include

include

using namespace std;

define INF 0x3f3f3f3f

int n,m,h[30],ans,maxx,a,minn,pos; int main(){

cin>>n>>m;
for(int i=1;i<=n;i++){
    cin>>a;
    minn=INF;
    for(int j=1;j+a-1<=m;j++) {
    	maxx=0;
        for(int k=1;k<=a;k++){
            maxx=max(maxx,h[k+j-1]);
        }
        if(maxx<minn){
			minn=maxx,pos=j;
		}
    }
    for(int i=1;i<=a;i++){
		h[i+pos-1]=minn+a;
	}
}
for(int i=1;i<=n;i++){
    ans=max(ans,h[i]);
}
cout<<ans;
return 0;

}