# include <bits/stdc++.h>
using namespace std;
# define IOS ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
# define int long long
# define lowbit(x) (x & (-x))
# define fi first
# define se second
# define all(x) x.begin(), x.end()
// # define endl '\n'

inline int Read();

typedef pair<int, int> PII;
const int INF = 0x3f3f3f3f;
const int MOD = 998244353;
const int N = 1e6 + 10;
const double eps = 1e-8;

map <int, int> mp;
vector <int> v;

int exgcd(int a, int b, int &x, int &y){
    if(b == 0) {x = 1, y = 0; return a; }
    int d = exgcd(b, a % b, y, x);
    y -= a / b * x;
    return d;
}
void Solve(){
    int h, m, a;
    cin >> h >> m >> a;
    double t = (double)a * 2 / (h - 1);
    int ans = (h - 2) * (int)t;
    // cout << "ans:" << ans <<"\n";
    int p = h * m % (h - 1);
    // cout <<"p:" << p <<"\n";
    int x, y;
    int d = exgcd(p, h - 1, x, y);
    x *= -a / d;
    int mod = (h - 1) / d;
    // cout << "mod:" <<mod <<'\n';
    x = (x % mod + mod) % mod;
    // cout << "x1: "<< x <<"\n";
    int sum = 0, xx = x;
    sum = (h - 1 - x) / mod + 1;
    ans += sum;
    d = exgcd(p, h - 1, x, y);
    x *= a / d;
    x = (x % mod + mod) % mod;
    // cout << "x2: "<< x <<"\n";
    if(xx != x){
        sum = (h - 1 - x) / mod + 1;
        ans += sum;
    }
    ans += 1;
    cout << ans <<"\n";
}
signed main(){
    IOS;
    int T = 1;
    // cin >> T;
    while (T--) 
        Solve();
    return 0;
}
inline int Read(){
    int x = 0, f = 1; char c = getchar();
    while (c < '0' || c > '9'){ if (c == '-') f = -1; c = getchar();}
    while (c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
    return x * f;
}