求调10分

#include<bits/stdc++.h>
using namespace std;
int n,x,a[100005];
int cnt;
long long s[100005];
int main(){
	cin>>n>>x;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		
	}
	if(a[1]+a[2]>x){
		cnt+=a[1]+a[2]-x;
		if(a[2]<cnt) {
			a[2]=0;
			a[1]-=cnt-a[2];
		}   else{
			a[2]-=cnt;
		}
	}
	for(int i=2;i<=n;i++){
		int sum=0;
		if(a[i]+a[i-1]>x){
			sum+=a[i]+a[i-1]-x;
			cnt+=a[i]+a[i-1]-x;
			if(a[i-1]<sum){
				a[i-1]=0;
				sum-=a[i-1];
				if(a[i]<sum){
					a[i]=0;
					sum-=a[i];
				}else a[i]-=sum;
			}else a[i-1]-=sum;
		}
		
	}
	cout<<cnt;
	return 0;
}