#include<iostream>
#include<vector>
#include<string>

using namespace std;

int main()
{
    setlocale(0,"");
    string s;
    cin >> s;
    vector<int>freq(128);

    for (int i = 0; i < s.length() + 1; i++)
        freq[s[i]]++;

    string s1;
    cin >> s1;

    vector<int>freq1(128);

    for (int i = 0; i < s1.length() + 1; i++)
        freq1[s1[i]]++;

    string s2;
    cin >> s2;
    vector<int>freq2(128);

    for (int i = 0; i < s2.length() + 1; i++)
        freq2[s2[i]]++;

    string s3;
    cin >> s3;
    vector<int>freq3(128);

    for (int i = 0; i < s3.length() + 1; i++)
        freq3[s3[i]]++;

    int counter = 0;
    int counter1 = 0;
    int counter2 = 0;
    int counter3 = 0;

    for (int i = 0; i < 128; i++) {
        if (freq[i] > 0) counter++;

        if (freq1[i] > 0) counter1++;

        if (freq2[i] > 0) counter2++;

        if (freq3[i] > 0) counter3++;
    }

    int m = -1;
    int m1 = -1;
    int m2 = -1;
    int m3 = -1;

    if (counter == 9 || counter1 == 9 || counter2 == 9 || counter3 == 9) m = 4;
    if (counter == 15 || counter1 == 15 || counter2 == 15 || counter3 == 15) m1 = 5;
    if (counter == 14 || counter1 == 14 || counter2 == 14 || counter3 == 14) m2 = 3;
    if (counter == 1 || counter1 == 1 || counter2 == 1 || counter3 == 1) m3 = 2;

    int result = (m+m1+m2+m3)/4;
    cout << m << "\n";
}