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

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

C.printf("%ld\n", (function (n, m)
	if n < m * 1000LL then return 0LL end
	return n/m - n/m%1000
end)(C.atol(io.stdin:read("*l")), C.atol(io.stdin:read("*l"))))