#include <stdio.h>
#include <stdint.h>
uint16_t hex_to_uint(const char *str) {
// Your logic here
uint16_t value=0;
int digit;
for(int i=0;str[i]!='\0';i++){
if(str[i]>='0'&&str[i]<='9'){
digit=str[i]-'0';
}
else if(str[i]>='A'&&str[i]<='F'){
digit=str[i]-'A'+10;
}
else{
digit=str[i]-'a'+10;
}
value=value*16+digit;
}
return value;
}
int main() {
char hex[10];
scanf("%s", hex);
printf("%u", hex_to_uint(hex));
return 0;
}