#include <stdio.h>

int main(void){
	int i,n,len,sum=0;
	int s[15];
	
	scanf("%d", &n);
	
	for(i=0,len=0;n>0;i++,len++){
		s[i] = (n%10);
		s[i+1] = '\0';
		n /= 10;
	}
	
	for(i=len-1;i>0;i--){
		int j,maxNum=s[i]+1, pos=i;
		for(j=i-1;j>=0;j--){
			if(maxNum <= s[j]){
				maxNum = s[j];
				pos = j;
			}
		}
		if(pos != i){
			int tmp = s[i];
			s[i] = s[pos];
			s[pos] = tmp;
			
			
			break;
		}
	}
	
	for(i=len-1;i>=0;i--){
		sum = sum*10 + s[i];
	}
	
	printf("%d\n", sum);
	
	return 0;
}