#include <stdio.h>
#include <string.h>

int main( int argc, char *argv[] )
{
    int k;
    char s[110];

    scanf( "%d", &k );
    scanf( "%s", s );

    if( strlen( s ) > k ) {
        s[k] = '\0';
        strcat( s, "..." );
    }

    printf( "%s\n", s );
}
