import sys read=sys.stdin.buffer.read;readline=sys.stdin.buffer.readline;input=lambda:sys.stdin.readline().rstrip() import bisect,string,math,time,functools,random,fractions from bisect import* from heapq import heappush,heappop,heapify from collections import deque,defaultdict,Counter from itertools import permutations,combinations,groupby rep=range;R=range def I():return int(input()) def LI():return [int(i) for i in input().split()] def LI_():return [int(i)-1 for i in input().split()] def AI():return map(int,open(0).read().split()) def S_():return input() def IS():return input().split() def LS():return [i for i in input().split()] def NI(n):return [int(input()) for i in range(n)] def NI_(n):return [int(input())-1 for i in range(n)] def NLI(n):return [[int(i) for i in input().split()] for i in range(n)] def NLI_(n):return [[int(i)-1 for i in input().split()] for i in range(n)] def StoLI():return [ord(i)-97 for i in input()] def ItoS(n):return chr(n+97) def LtoS(ls):return ''.join([chr(i+97) for i in ls]) def RLI(n=8,a=1,b=10):return [random.randint(a,b)for i in range(n)] def RI(a=1,b=10):return random.randint(a,b) def INP(): N=10 n=random.randint(1,N) a=RLI(n,0,n-1) return RI(0,100),RI(1,100),RI(1,100) def Rtest(T): case,err=0,0 for i in range(T): inp=INP() a1=naive(*inp) a2=solve(*inp) if a1!=a2: print(inp) print('naive',a1) print('solve',a2) err+=1 case+=1 print('Tested',case,'case with',err,'errors') def GI(V,E,ls=None,Directed=False,index=1): org_inp=[];g=[[] for i in range(V)] FromStdin=True if ls==None else False for i in range(E): if FromStdin: inp=LI() org_inp.append(inp) else: inp=ls[i] if len(inp)==2:a,b=inp;c=1 else:a,b,c=inp if index==1:a-=1;b-=1 aa=(a,c);bb=(b,c);g[a].append(bb) if not Directed:g[b].append(aa) return g,org_inp def GGI(h,w,search=None,replacement_of_found='.',mp_def={'#':1,'.':0},boundary=1): #h,w,g,sg=GGI(h,w,search=['S','G'],replacement_of_found='.',mp_def={'#':1,'.':0},boundary=1) # sample usage mp=[boundary]*(w+2);found={} for i in R(h): s=input() for char in search: if char in s: found[char]=((i+1)*(w+2)+s.index(char)+1) mp_def[char]=mp_def[replacement_of_found] mp+=[boundary]+[mp_def[j] for j in s]+[boundary] mp+=[boundary]*(w+2) return h+2,w+2,mp,found def TI(n):return GI(n,n-1) def accum(ls): rt=[0] for i in ls:rt+=[rt[-1]+i] return rt def bit_combination(n,base=2): rt=[] for tb in R(base**n):s=[tb//(base**bt)%base for bt in R(n)];rt+=[s] return rt def gcd(x,y): if y==0:return x if x%y==0:return y while x%y!=0:x,y=y,x%y return y def YN(x):print(['NO','YES'][x]) def Yn(x):print(['No','Yes'][x]) def show(*inp,end='\n'): if show_flg:print(*inp,end=end) mo=10**9+7 #mo=998244353 inf=float('inf') FourNb=[(-1,0),(1,0),(0,1),(0,-1)];EightNb=[(-1,0),(1,0),(0,1),(0,-1),(1,1),(-1,-1),(1,-1),(-1,1)];compas=dict(zip('WENS',FourNb));cursol=dict(zip('LRUD',FourNb)) alp=[chr(ord('a')+i)for i in range(26)] #sys.setrecursionlimit(10**7) def gcj(c,x): print("Case #{0}:".format(c+1),x) ## Verified by Yukicoder 1073 ## https://yukicoder.me/problems/no/1073 ## ## Matrix Class supporting operators +, -, *, %, +=, -=, *=, %= ## *, *= allows int/float/complex ## ** or pow(self,p,mod) for the size N*N matrix is implemented by Repeated squaring. O(N^3*log(p)) ## ## Constructor: matrix(array), where array is 1D or 2D array. 1-dimensional array X is modified as 2D array of [X]. ## ## methods ## T(): returns transposed matrix ## resize((n,m),fill=0): changes the matrix instance into the new shape (n * m), missing entries are filled with "fill" (default value is zero). class matrix: class MulShapeError(Exception): "mult is not applicable between the two matrices given" pass def __init__(self,arr_input): if hasattr(arr_input[0],"__getitem__"): self.arr=arr_input else: self.arr=[arr_input] self.shape=(len(self.arr),len(self.arr[0])) def __getitem__(self,key): return self.arr[key] def __setitem__(self,key,value): self.arr[key]=value def __iter__(self): return iter(self.arr) def __add__(self,B): if type(B)!=matrix: return NotImplemented if B.shape!=self.shape: return NotImplemented rt=[[0]*self.shape[1] for i in range(self.shape[0])] for i in range(self.shape[0]): for j in range(self.shape[1]): rt[i][j]=self.arr[i][j]+B.arr[i][j] return matrix(rt) def __iadd__(self,B): return self.__add__(B) def __sub__(self,B): if type(B)!=matrix: return NotImplemented if B.shape!=self.shape: return NotImplemented rt=[[0]*self.shape[1] for i in range(self.shape[0])] for i in range(self.shape[0]): for j in range(self.shape[1]): rt[i][j]=self.arr[i][j]-B.arr[i][j] return matrix(rt) def __isub__(self,B): return self.__sub__(B) def __mul__(self,M): if type(M) in [int,float,complex]: M=matrix([[M*(i==j) for j in range(self.shape[1])] for i in range(self.shape[1])]) if type(M)!=matrix: return NotImplemented if M.shape[0]!=self.shape[1]: raise matrix.MulShapeError("mult is not applicable between the matrices of shape "+str(self.shape)+" and "+str(M.shape)) ra,ca=self.shape rb,cb=M.shape c=[[0]*cb for i in range(ra)] for i in range(ra): for j in range(cb): for k in range(ca): c[i][j]^=self.arr[i][k]*M.arr[k][j] return matrix(c) def __imul__(self,M): return self.__mul__(M) def __rmul__(self,M): if type(M) in [int,float,complex]: M=matrix([[M*(i==j) for j in range(self.shape[1])] for i in range(self.shape[1])]) if type(M)!=matrix: return NotImplemented if M.shape[0]!=self.shape[1]: raise matrix.MulShapeError("mult is not applicable between the matrix shape "+str(self.shape)+" and "+str(M.shape)) ra,ca=M.shape rb,cb=self.shape c=[[0]*cb for i in range(ra)] for i in range(ra): for j in range(cb): for k in range(ca): c[i][j]^=M.arr[i][k]*self.arr[k][j] return matrix(c) def __mod__(self,p): if type(p)!=int: return NotImplemented c=[[0]*self.shape[1] for i in range(self.shape[0])] for i in range(self.shape[0]): for j in range(self.shape[1]): c[i][j]=self.arr[i][j]%p return matrix(c) def __imod__(self,p): return self.__mod__(p) def __pow__(self,p,mod=10**9+7): if type(p)!=int or self.shape[0]!=self.shape[1]: return NotImplemented A=matrix(self.arr) R=matrix([[1*(i==j) for j in range(self.shape[0])] for i in range(self.shape[0])]) while p>0: if p&1: R*=A R%=mod A*=A A%=mod p>>=1 return R def __neg__(self): return self.__mul__(-1) def __str__(self): rt='[' for i in self.arr: rt=rt+str(i)+",\n" return rt[:-2]+']' def T(self): rt=[[0]*self.shape[0] for i in range(self.shape[1])] for i in range(self.shape[0]): for j in range(self.shape[1]): rt[j][i]=self.arr[i][j] return matrix(rt) def resize(self,new_shape,fill=0): t_arr=[] for i in self.arr: t_arr+=i t_arr.reverse() n,m=new_shape self.shape=(n,m) self.arr=[[fill]*m for i in range(n)] for i in range(self.shape[0]): for j in range(self.shape[1]): if t_arr: self.arr[i][j]=t_arr.pop() return def view(self): for i in self.arr: print(i) show_flg=False show_flg=True ans=0 n,k=LI() a=LI() x=[0]+([1]+[0]*n)*(n-1) x=x[:n*(n-1)]+[1]*n m=matrix(x) m.resize((n,n)) a=matrix(a) a.resize((n,1)) m**=k+1 y=m*a print(y[-1][0])