/*

Author: Haze

2024/9/4

*/

#include <bits/stdc++.h>

#define irep(i, l, r) for(int i = (l); i <= (r); ++ i)
#define drep(i, r, l) for(int i = (r); i >= (l); -- i)
#define IOS ios::sync_with_stdio(false), cin.tie(nullptr);
using namespace std;
typedef long long ll;

inline ll readL() {
    ll s = 0;
    bool fl = false;
    char ch = (char) getchar();
    while (!isdigit(ch)) {
        if (ch == '-')fl = true;
        ch = (char) getchar();
    }
    while (isdigit(ch)) {
        s = s * 10 + (ch ^ 48);
        ch = (char) getchar();
    }
    return fl ? -s : s;
}

inline ll read() {
    return (readL());
}

const int mod = 1000000000 + 7;
const int itinf = 1000000999;
const ll llinf = 2e18;
const int N = 500099;

void solve() {
    ll n = read(), m = read(), s = readL();
    ll ans = 0;

    ll Rd = s / (n - 1), Ld = 0, Lr = 0, Rr = s % (n - 1), t1 = m / (n - 1), t2 = m % (n - 1);
    if(n - 2 - s >= 0)Ld = (n - 2 - s) / (n - 1), Lr = (n - 2 - s) % (n - 1);
    else Ld = 0, Lr = n - 2 - s;
    auto update =
            [&n](ll &d, ll &r, ll &vd, ll &vr){
        d += vd, r += vr;
        while(r >= n - 1)
            ++ d, r -= n - 1;
    };

    for(ll i = 0; i < n; ++ i){
//        ll tim = i * m;
//        ll r = (s + tim) / (n - 1), l = (tim - s + n - 2) / (n - 1);
//        r = min(r, m - 1);
//        l = max(l, 0ll);
        Rd = min(Rd, m - 1);
        ans += (Rd - Ld + 1);
//        cerr << Ld << ' ' << Lr<< ' ' << Rd << ' ' << Rr<< endl << l << ' ' << r << endl;
        update(Ld, Lr, t1, t2);
        update(Rd, Rr, t1, t2);
    }
    cout << ans;
}

int main() {
    // IOS
    int T = 1;
    while (T--) {
        solve();
    }
    return 0;
}