// Sat Dec  3 16:38:39 EST 2011
#include <string>
#include <vector>
#include <list>
#include <algorithm>
#include <map>
#include <set>
#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;

#define VIT(i, v) for (i = 0; i < v.size(); i++) 
#define IT(it, ds) for (it = ds.begin(); it != ds.end(); it++)
#define FUP(i, n) for (i = 0; i < n; i++)
#define O1(v) cout << v << endl
#define O2(v1, v2) cout << v1 << " " << v2 << endl
#define O3(v1, v2, v3) cout << v1 << " " << v2 << " " << v3 << endl
#define OVEC(v) { int iii; VIT(iii, v) cout << v[iii] << " " ; cout << endl; }
typedef vector <string> SVec;

class Trekking {
  public:
    int findCamps(string trail, vector <string> plans);
};

int Trekking::findCamps(string trail, vector <string> plans)
{
  int min, i, nc, j;

  min = trail.size()+1;

  for (i = 0; i < plans.size(); i++) {
    nc = 0;
    for (j = 0; j < trail.size(); j++) {
      if (plans[i][j] == 'C') {
        if (trail[j] == '.') {
          nc++;
        } else {
          nc = trail.size()+1;  
        }
      }
    }
    if (nc < min) min = nc;
  }
  if (min == trail.size()+1) return -1;
  return min;
}