#include <string.h>
main(){
    char    s[128];
    int     len;
    scanf("%s",s);
    len = strlen(s);
    if( s[0] == '-' || len < 3 ) {
        printf("0\n");
    } else {
        s[len-2] = '\0';
        printf("%s\n",s);
    }
}