#include<stdio.h> int main() { int a,b,c,d,abcd,sum;//简单易懂； scanf("%d",&abcd); a=abcd/1000; b=(abcd-a1000)/100; c=(abcd-a1000-b100)/10; d=(abcd-a1000-b100-c10); sum=d1000+c100+b*10+a; printf("%d",sum); return 0; }