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


#define inFile "1003.in"
#define outFile "1003.out"

struct node {
    long c1,c2 ;
    int xx ;
    struct node /**/ *next ;
} ;


FILE *fp1,*fp2 ;
node /**/ *Head ;
int Flag , Result ;

void Init () ;
void Work () ;
void Done ( int , int , int ) ;
void Link ( int v1 , int v2 , int shi );
void Remove ( node * now )             ;

void main( int argc , char * argv[] )
{
//    fp1 = fopen ( argv [1 ] , "rt" ) ;
//    fp2 = fopen ( argv [2 ] , "wt" ) ;
    Init () ;
    Work () ;
//    fclose ( fp1 ) ;
//    fclose ( fp2 ) ;

}

void Init ()
{

    Head = (struct node * ) /**/malloc (sizeof ( struct
node ) ) ;
    Head -> c1 = 0 ;
    Head -> c2 = 0 ;
    Head -> xx = 0 ;
    Head -> next = NULL ;
}

void Work ()
{
    long www ;
    int num ;
    long v1, v2 ;
    char ss [10 ] ;
    scanf (  "%ld" , &www ) ;
    while ( www != -1 ) {
        Flag = 1 ;
        scanf (   "%d" , &num ) ;
        for ( int i = 0 ; i < num ; i ++ ) {
            scanf (   "%ld %ld %s" , &v1 , &v2 ,
ss ) ;
            if ( Flag ) {
                if ( strcmp ( ss , "even" ) ==
0 )
                    Done ( v1 , v2 , 2 ) ;
                else Done ( v1 , v2 , 1 ) ;
                Result = i ;
            }
        }
        printf (   "%d\n" , Result ) ;
        scanf (   "%ld" , &www ) ;
    }
}

void Done ( int v1 , int v2 , int shi )
{
    node /**/ *p ;
    int mode = 0 ;

    if ( Head -> next == NULL )
        Link ( v1,v2,shi ) ;
    else {
        p = Head -> next ;
        while ( p ) {
            if ( p->c1 == v1 ) {
                mode = 1 ;
                break ;
            } else if ( p->c2 == v2 ) {
                mode = 2;
                break ;
            }
            p = p -> next ;
        }
        if ( mode == 0 ) {
            Link ( v1,v2,shi ) ;
        } else if ( mode == 1 ) {
            if ( p->c2 == v2 ) {
                if ( p->xx != shi )
                    Flag = 0 ;
            } else if ( p->c2 > v2 ) {
                int max = p->c2 ;
                if ( p->xx == shi ) {
                    p->xx = 2;
                    p->c2 = v2 ;
                    Done ( v2+1 , max ,
2 ) ;
                } else {
                    p->xx = shi ;
                    Done ( v2+1 , max ,
1 ) ;
                }
            } else {
                if ( p ->xx == shi )
                    Done ( p->c2 , v2-1 ,
2 ) ;
                else Done ( p->c2 , v2-1 , 1 ) ;
            }
        } else if ( mode == 2 ) {
            if ( p->c1 == v1 ) {
                if ( p->xx != shi )
                    Flag = 0 ;
            } else if ( p->c1 < v1 ) {
                int max = p->c1 ;
                if ( p->xx == shi ) {
                    p->xx = 2;
                    p->c1 = v1 ;
                    Done ( max , v1-1 ,
2 ) ;
                } else {
                    p->xx = shi ;
                    Done ( max, v1-1 , 1 ) ;
                }
            } else {
                if ( p ->xx == shi )
                    Done ( v1 , p->c1-1 ,
2 ) ;
                else Done ( v1 , p->c1-1 , 1 ) ;
            }




        }


    }


}

void Link ( int v1 , int v2 , int shi )
{
    node /**/ *pp ;

    pp = ( struct node* ) /**/malloc ( sizeof ( struct node )) ;
    pp -> c1 = v1 ;
    pp -> c2 = v2 ;
    pp -> xx = shi ;
    pp -> next = Head -> next ;
    Head -> next = pp ;
}

void Remove ( node * now )
{
    node /**/ *p = now -> next ;
    now -> next = p -> next ;
    /**/free ( p ) ;
}