#include<stdio.h>
int main()
{
    int m,n,t,s;
    scanf("%d",&m);
    n=m/10;
    t=m%10;
    s=t*10+n;
    if(s>m)
        printf("%d",s);
    else
        printf("%d",m);
    return 0;
}

/**************************************************************
	Problem: 1625
	User: admin
	Language: C
	Result: Accepted
	Time:10 ms
	Memory:1144 kb
****************************************************************/