/*
ID: indy901
PROG: beads
LANG: C
*/

#include <stdio.h>
#include <stdlib.h>

int N;
int i;
int j;
int maxBeads;
int gotColor;
char color;
char* beads;
FILE* fp;

void countBeads( int i ) {
	if ( beads[ i ] == 'w' )
		maxBeads++;
	else if ( gotColor == 1 ) {
		if ( color != beads[ i ] )
			break;
		else
			maxBeads++;
	}
	else {
		color = beads[ i ];
		gotColor = 1;
		maxBeads++;
	}
}

int main() {
	fp = fopen( "beads.in" , "r" );
	fscanf( fp , "%d" , &N );
	beads = ( char* )malloc( sizeof( char ) * N );
	fscanf( fp , "%s" , beads );
	maxBeads = 0;
	gotColor = 0;
	for ( i = 0; i < N; i++ )
		countBeads( i );
	for ( j = N; j > i; j-- )
		countBeads( j );
	fclose( fp );
	fp = fopen( "beads.out" , "w" );
	fprintf( fp , "%d\n" , maxBeads );
	fclose( fp );
	free( beads );
	return 0;
}