看标程OI选手还有这样的操作，记录下以备不时之需。
1 inline int IN(){View Code
2 char ch = getchar(); int x = 0, f = 0;
3 while(ch < '0' || ch > '9') ch = getchar(), f = (ch == '-');
4 while(ch >= '0' && ch <= '9'){
5 x = (x << 1) + (x << 3) + ch - 48;
6 ch = getchar();
7 }
8 return f ? (-x) : x;
9 }