#include using namespace std; #define inf 1000000000 #define INF 1000000000000000 #define ll long long #define ull unsigned long long #define M (int)(1e9+7) #define P pair #define PLL pair #define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++) #define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--) #define rep(i,n) FOR(i,0,n) #define rrep(i,n) RFOR(i,n,0) #define all(a) a.begin(),a.end() #define IN(a,n) rep(i,n){ cin>>a[i]; } const int vx[4] = {0,1,0,-1}; const int vy[4] = {1,0,-1,0}; #define PI 3.14159265 #define F first #define S second #define PB push_back #define EB emplace_back #define int ll void init(){ cin.tie(0); ios::sync_with_stdio(false); } int n,k; int a[1100]; #define mat vector> mat mul_mat(mat &a, mat &b){ mat res(a.size(), vector(b[0].size(),0)); rep(i, a.size())rep(k, b.size())rep(j, b[0].size()){ res[i][j] = (res[i][j] + (a[i][k] * b[k][j])%M)%M; } return res; } mat power_mat(mat &a,int k){ mat res(a.size(), vector(a.size())); rep(i, a.size()) res[i][i] = 1; while(k > 0){ if(k&1) res = mul_mat(res,a); a = mul_mat(a,a); k >>= 1; } return res; } void solve1(){ vector f(k+1); int sum=0; rep(i,n){ f[i]=a[i]; sum+=f[i]; } FOR(i,n,k){ f[i]=sum; sum-=f[i-n]; sum+=f[i]; sum%=M; } int ans=0; rep(i,k){ ans+=f[i]; //cout<(n,0)); rep(i,n){ s[i][0]=1; } rep(i,n-1){ s[i][i+1]=1; } mat t(2*n,vector(2*n,0)); rep(i,n){ rep(j,n){ t[i][j]=s[i][j]; if(i==j){ t[i+n][i]=1; t[i+n][i+n]=1; } } } s = power_mat(s,k-n); int res=0; rep(i,n){ res+=(a[n-1-i]*s[i][0])%M; res%=M; } t = power_mat(t,k-n+1); t[n][0]--; int ans=0; rep(i,n){ ans+=(a[n-1-i]*t[i+n][0])%M; ans%=M; ans+=a[i]; ans%=M; } cout<>n>>k; rep(i,n){ cin>>a[i]; } if(k<=1000000) solve1(); else solve2(); }