#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    if(gcd(a, gcd(b, c)) > 1){
        puts("0");
        return 0;
    }
    int M = 2500000;
    vector<bool> x(M+1, 0);
    x[0] = 1;
    int ans = 0;
    for (int i = 0; i <= M; ++i) {
        if(!x[i]) ans++;
        else {
            if(i+a <= M) x[i+a] = 1;
            if(i+b <= M) x[i+b] = 1;
            if(i+c <= M) x[i+c] = 1;
        }
    }
    cout << ans << "\n";
    return 0;
}