#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int a; cin>>a; int b=a/1000; int c=(a/100)%10; int d=(a/10)%10; int e=a%10; int f=c*1000+b*100+e*10+d*1; cout<<f; return 0; }