View Compilation Error

0_0_30171865_16372.cpp: In function 'void build(int, int, int)':
0_0_30171865_16372.cpp:42:67: error: 'struct node' has no member named 'pos'
     ns[rt].rsum = ns[rt].lsum = ns[rt].msum = ns[rt].sum = ns[rt].pos = 0;
                                                                   ^