import std.stdio;
import std.string;
import std.conv;
import std.algorithm;
import std.array;
import std.math;
import std.range;
import std.bigint;

void main() {
  auto l = readln.chomp.split.map!(to!long).array;
  long a = l[0], b = l[1], c = l[2];

  long lb = 1L, rb = 1e18.to!long, mid;

  while (rb - lb > 1) {
    mid = (lb + rb) / 2;
    long money = b * (mid / a) + (mid - mid / a);

    if (money > c) {
      rb = mid;
    }
    else if (money < c) {
      lb = mid;
    }
    else {
      rb = mid;
      break;
    }
  }

  rb.writeln;
}