#include<iostream> int main(){ int x,b,c,d,e,t,q,w,r; scanf("%d",&x); q=x%1000; w=q%100; r=w%10; b=(x-q)/1000; c=(q-w)/100; d=(w-r)/10; e=r/1; printf("%d%d%d%d",e,d,c,b); return 0; }