1 #include <iostream>
2 #include <cstdio>
3 #include <vector>
4 #include <queue>
5 #include <map>
6 #include <cmath>
7 #include <stack>
8 #include <cstring>
9 #include <algorithm>
10 #include <cstdlib>
11 #define FOR(i,x,n) for(long i=x;i<n;i++)
12 #define ll long long int
13 #define INF 0x3f3f3f3f
14 #define MOD 1000000007
15 #define MAX_N 50005
16
17 using namespace std;
18
19 int a[200];
20 char s[20];
21
22 int main()
23 {
24 //freopen("input1.txt", "r", stdin);
25 //freopen("data.out", "w", stdout);
26 ll n;
27 int cou=0;
28 ll ans=0;
29 scanf("%s",s);
30 int len=strlen(s);
31 FOR(i,0,len){
32 if(s[i]>='A'&&s[i]<='F'){
33 ans+=(s[i]-'A'+10)*pow(16,len-i-1);
34 }else{
35 ans+=(s[i]-'0')*pow(16,len-i-1);
36 }
37 }
38 printf("%lld",ans);
39 //fclose(stdin);
40 //fclose(stdout);
41 return 0;
42 }
