#include <stdio.h>
int main(void){
    long int A,B;
    long int count = 0;

    scanf("%ld %ld",&A,&B);

    if(A > B){
        count += A - B - 1;
        count += 2000000000 - A;
    }else{
        count += B - A - 1;
        count += A - 1;
    }

    printf("%ld\n",count);
    return 0;
}