20240418

# a,b,c,d=map(int,input().split())# s=0# if d==1:#     print(a)# else:#     for i in range(d-1):#         a=a*(b)+c#         s=a#         a=s#     print(s)# a=int(input())# s=0# for i in range(a+1):#     if i%10==1:#         s+=1# print(s)# n=int(input())# a=list(map(int,input().split()))# print(max(a))# a,b=map(int,input().split())# if a%2==1 and b%2==0 or a%2==0 and b%2==1:#     print(a//2+1+b//2*10 if a%2==1 and b%2==0 else a//2*10+b//2+1)# elif a%2==0 and b%2==0 or a%2==1 and b%2==1:#     print(a//2*10+b//2*10 if a%2==0 and b%2==0 else a+b)# a=int(input())# for i in range(1,a+1):#     if a%i==0:#         print(i,end=' ')# a=int(input())# s=0# for i in range(1,a+1):#     if a%i==0:#        s+=1# if s==2:#     print("prime")# else:#     print("not prime")# a,k=map(int,input().split())# print(a**k)# a=int(input())# s=0# for i in range(a-1,1,-1):#     a=a*i# print(a)# a=int(input())# x=list(map(int,input().split()))# print(x[0],x[a//2+a%2-1],x[a-1])# a,b=map(int,input().split())# s=0# for i in range(a,b+1):#     if i%2==1:#         s+=i#         if a<0:#             print('+',i,sep='',end='')#         if a>0 and i==a#             print(i,sep='',end='')#         else:#             print('+',i,sep='',end='')#     else:#         s-=i#         print('-',i,sep='',end='')# print('=',s,sep='')# a=int(input())# for i in range(a+1):##     if a-i//a==0:#         max=i#         if i==a:#             print(max)#             break