代码如下：

#include<stdio.h>
#define min_n(a,b) a<b?a:b
int main()
{
    int n,x;
    scanf("%d%d",&n,&x);
    int a[n],b[n];
    long long ans1=0,ans2=0;
    for(int i=0;i<n;i++){
        scanf("%d",a+i);
        b[i]=a[i];
    }
    for(int i=0;i<n-1;i++){
        int tmp;
        if(a[i]+a[i+1]>x){
            tmp=a[i+1];
            a[i+1]=x-a[i];
            ans1+=tmp-a[i+1];
        }
        if(b[i]+b[i+1]>x){
            tmp=b[i];
            b[i]=x-b[i+1];
            ans2+=tmp-b[i];
        }
    }
    printf("%lld",min_n(ans1,ans2));
    return 0;
}