#include<set> #include<cmath>#include<ctime>#include<queue>#include<stack>#include<cstdio>#include<vector>#include<cstring>#include<cstdlib>#include<iostream>#include<algorithm>#define N 50001using namespace std;typedef long long ll;ll f[N],s[N],q[N],h,t,l,n;inline ll sqr(ll k){    return k*k;}inline ll x(ll k){    return k+s[k];}inline ll y(ll k){    return f[k]+sqr(x(k));}inline double cmp(ll p,ll q){    return (double)(y(q)-y(p))/(double)(x(q)-x(p));}inline ll g(ll k){    return k+s[k]-l;}inline void init(){    scanf("%lld%lld",&n,&l);    for(ll i=1;i<=n;i++){        scanf("%lld",&s[i]);        s[i]+=s[i-1];    }    for(ll i=1,k;i<=n;i++){        k=g(i)<<1;        while(h<t&&cmp(q[h],q[h+1])<k) h++;        f[i]=f[q[h]]+sqr(x(q[h])-g(i)+1);        while(h<t&&cmp(q[t],i)<cmp(q[t-1],q[t]))            t--;        q[++t]=i;    }    printf("%lld\n",f[n]);}int main(){    freopen("toy.in","r",stdin);    freopen("toy.out","w",stdout);    init();    fclose(stdin);    fclose(stdout);    return 0;}