#include <stdio.h>
#include <stdint.h>
uint32_t extract_field(uint32_t reg, uint8_t pos, uint8_t len) {
// Your code here
unsigned int sum=0,r,i=1;
for(int pos1=pos;pos1<pos+len;pos1++,i=i*2)
{
r=(reg>>pos1&1);
sum=sum+(r*i);
}
return sum;
}
int main() {
uint32_t reg;
uint8_t pos, len;
scanf("%u %hhu %hhu",®, &pos, &len);
printf("%u", extract_field(reg, pos, len));
return 0;
}