#include<bits/stdc++.h>
main(){
    char S[10];
    scanf("%s",S);
    for(int j = 0;j < strlen(S)-2;j++){
        int max = S[j]-'0';
        int index = j;
        for(int i = strlen(S)-1;i >= j+1;i--){
            if(S[i]-'0' > max){
                max = S[i] - '0';
                index = i;
            }
        }
        if(S[j]-'0' < max){
            char c = S[j];
            S[j] = S[index];
            S[index] = c;
            break;
        }
    }
    printf("%s",S);
}