#include <iostream>
using namespace std;
int two_to(int a){
int power = 1;
for (int i = 0; i < a; i++){
power = 2 * power;
}
return power;
}
int min(int a, int b){
if (a < b) return a;
return b;
}
int main() {
int k;
cin >> k;
int value[20][1 << 19];
int suma_galezi[20][1 << 19];
for (int i = 0; i < k; i++){
for (int j = 0; j < two_to(i); j++){
cin >> value[i][j];
}
}
for (int j = 0; j < two_to(k-1); j++){
suma_galezi[k-1][j] = value[k-1][j];
}
for (int i = k - 2; i >= 0; i--){
for (int j = 0; j < two_to(i); j++){
suma_galezi[i][j] = value[i][j] + min(
suma_galezi[i+1][2*j],
suma_galezi[i+1][2*j + 1]
);
}
}
cout << suma_galezi[0][0] << "\n";
return 0;
}
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