#include <stdio.h>

int main(){
	int b, s, d, j;
	scanf("%d",&b);
	j=b%10;
	d=(b/10)%10;
	s=(b/100)%10;
	b=(b/1000)*1000+100*j+10*d+s;
	printf("%d\n",b);
	return 0;
}