local ffi = require 'ffi'
local C = ffi.C

ffi.cdef [[
long atol(const char *);
int printf(const char *, ...);
]]

C.printf("%ld\n", (function (f, s)
	return f(s)
end)(function (s)
	local a,b,c = s:match("(%d+)%s(%d+)%s(%d+)")
	a,b,c = C.atol(a),C.atol(b),C.atol(c)

	if a > c then return c end

	local d = a-1LL+b
	return c/d*a + (c%d < a and c%d or a)
end, io.stdin:read("*l")))