一个整数N。
对于40%的数据,1<=N<=1000
对于70%的数据,1<=N<=10000
对于100%的数据,1<=N<=100000
4
3
2018年真题精选
2194,2276,2277,2279,2280,2281,2282,2283,2284,2285,2286,2287,
2288,2291,2292,2294,2296
2194,2276,2277,2279,2280,2281,2282,2283,2284,2285,2286,2287,
2288,2291,2292,2294,2296