#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main(){
    char c[14];
    for(int i=0;i<14;i++){cin>>c[i];}
    vector<int> k(5,0);
    int l=-1;int n=-1;
    for(int i=0;i<13;i++){
        if(c[i]==c[i+1]&&i==l){
            k[n]++;
            l++;
        }else if(c[i]==c[i+1]){
            n++;
            k[n]++;
            l=i+1;
        }
    }
    sort(k.begin(),k.end());
    cout<<k[4]<<endl;
}