#include using namespace std; #define ll long long #define sci(x) scanf("%d",&x) #define scl(x) scanf("%lld",&x) #define scd(x) scanf("%lf",&x) #define pfi(x) printf("%d",x) #define pfl(x) printf("%lld",x) #define pfd(x) printf("%lf",x) #define pfc(x) printf("Case %d: ",x++) #define ps printf(" ") #define pn printf("\n") #define pb(x) push_back(x) #define ppb(x) pop_back(x) #define pf(x) push_front(x) #define ppf(x) pop_front(x) #define in(x,y) insert({x,y}) #define sv(a) sort(a.begin(),a.end()) int main() { //freopen("input.txt","r",stdin); //freopen("output.txt","w",stdout); int n; sci(n); ll ans=0,x=1; int data[n]; for(int i=0;i=0;i--) { ans+=(data[i]*x); x*=2; } cout<