slow slow read 板子
inline int read() { int ans=0; char last=' ',ch=getchar(); while(ch<'0'||ch>'9') last=ch,ch=getchar(); while(ch>='0'&&ch<='9') ans=ans*10+ch-'0',ch=getchar(); if(last=='-') ans=-ans; return ans; }
读字符,忽略掉没用的东西
inline char read() { char c; do { c=getchar(); }while(c==' '||c==' '||c=='