Binary Index Tree Template

namespace BIT{
  #define lowbits(x) (x&(-x))

  inline int read(){
      register int a=0,f=1;register char c;
      while((c=getchar())<'0')if(c=='-')f=-1;;
      while(c>='0')a=a*10+(c^48),c=getchar();
      return a*f;
  }
  int n,q,a,b,c,seg[MAXN],pos[MAXN];
  inline void update(int v, int val){
    for (int i=v;i<MAXN;i+=lowbits(i)) seg[i]+=val;
  }
  inline int query(int t, int f){
    int ans = 0;
    for (int i=f;i;i-=lowbits(i)) ans+=seg[i];
    for (int i=t-1;i;i-=lowbits(i)) ans-=seg[i];
    return ans;
  }
  inline void solve();
}