import std.stdio, std.string, std.conv, std.algorithm, std.numeric;
import std.range, std.array, std.math, std.typecons, std.container, core.bitop;

void main() {
    long a, b, c;
    scan(a, b, c);

    long btm = 0, top = 10L^^18;

    bool check (long k) {
        long money = k + (k / a) * (b - 1);
        return money >= c;
    }

    while (top - btm > 1) {
        long mid = (btm + top) / 2;

        if (check(mid)) {
            top = mid;
        }
        else {
            btm = mid;
        }
    }

    writeln(top);
}


void scan(T...)(ref T args) {
    string[] line = readln.split;
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront();
    }
    assert(line.empty);
}


void fillAll(R, T)(ref R arr, T value) {
    static if (is(typeof(arr[] = value))) {
        arr[] = value;
    }
    else {
        foreach (ref e; arr) {
            fillAll(e, value);
        }
    }
}