PAT(Basic Level)_1037_在霍格沃茨找零钱

#include<stdio.h>int main(){    long pg,ps,pk,ag,as,ak,dk;    scanf("%ld.%ld.%ld %ld.%ld.%ld",&pg,&ps,&pk,&ag,&as,&ak);    pk=(pg*17+ps)*29+pk;    ak=(ag*17+as)*29+ak;    dk=ak-pk;    if(dk<0){        putchar('-');        dk=-dk;    }    printf("%ld.%ld.%ld",dk/(17*29),dk/29%17,dk%29);    return 0;}