#include<stdio.h>
main(){
    char s1[8],s2[8];
    scanf("%s %s",s1,s2);
    int max = 0;
    int count = 0;
    for(int i = 0;i < 7;i++){
        if(s1[i] == 'x'){
            if(count > max){
                max = count;
            }
            count = 0;
        }else{count++;}
    }
    for(int i = 0;i < 7;i++){
        if(s2[i] == 'x'){
            if(count > max){
                max = count;
            }
            count = 0;
        }else{count++;}
    }
    printf("%d",max);
}