#include <iostream>
#include <algorithm>
using namespace std;
int main( void )
{
  int ret = 0, cnt = 0;
  for( int i=0; i<14; i++ ){
    char c;
    cin >> c;
    if( c == 'o' ){
      cnt++;
      ret = max( ret, cnt );
    } else {
      cnt = 0;
    }
  }
  cout << ret << endl;
}