#include <iostream>
#include <string>
using namespace std;

int main() {
string octalNum;
cin > octalNum;
int decimalNum = 0;
int base = 1;

for (int i = octalNum.size() - 1; i >= 0; --i) {
decimalNum += (octalNum[i] - '0') * base
base *= 8;
}

cout << de
imalNum << endl;
return 0;
}