[1－1×（0＋1）＋1÷1] ÷（1000－999）=7?:k1a7L3s's2L6x3f.B+F(V5u8X,c7j)e3M
算式：提示:O(U(f5U5[/I+H(u(z*u+M1a(V5u8X,c7j)e3M