/*

 ID: vincent63

 LANG: C

 TASK: beads

 */

 #include <stdio.h>

 #include<stdlib.h>

 #include<string.h>

 int findmax(char s[],int n){

     int i,j,count,max,l,r;

     char left,right;

     max=;

     count=;

     int p;

     for(i=,j=;j<n;i++,j++){

         l=i;

         r=j;

         while(s[l]=='w'){

             l--;

             count++;

         }

         while(s[r]=='w'){

             r++;

             count++;

         }

         left=s[l];

         right=s[r];

         for(;l>=;l--){

             if(s[l]==left||s[l]=='w'){

                 count++;

             }else{

                 break;

             }

         }

         for(;r<n;r++){

             if(s[r]==right||s[r]=='w'){

                 count++;

             }else{

                 break;

             }

         }

         if(count>max){

             max=count;

             p=i;

             //printf("%dth count:%d\n",p,count);

         }

         count=;

     }

     if(max>n/){

         return n/;

     }else{

         return max;

     }

 }

 int main () {

     FILE *fin  = fopen ("beads.in", "r");

     FILE *fout = fopen ("beads.out", "w");

     int n;

     char buf[];

     char res[];

     fgets(buf,,fin);

     n=atoi(buf); 

     char necklace[*n+];

     char buf2[n+];

     fgets(necklace,n+,fin);

     strcpy(buf2,necklace);

     strcat(necklace,buf2);

     int i;

     /*

     for(i=0;i<2*n;i++){

         printf("%c",necklace[i]);

     }

     printf("\n");

     */

     int max;

     max=findmax(necklace,*n);

     //itoa(max,res,10);

     sprintf(res,"%d\n",max);

     fputs(res,fout);

     //printf("%d\n",max);

     return ;

 }