#include <bits/stdc++.h>

using namespace std;

bool is_ok(int a, int b, int c, int d) {
	int x[] = {a, b, c, d};
	
	sort(x, x+4);

	return x[0] == x[3] || (x[0] == x[1] && x[2] == x[3]) || (x[0] != x[1] && x[1] != x[2] && x[2] != x[3]);
}

int main() {
	int a, b, c;
	cin >> a >> b >> c;

	for (int i = 0; i <= 3; i++) {
		if (is_ok(a, b, c, i)) {
			cout << i << endl;
			break;
		}
	}

	return 0;
}