View Compilation Error

0_0_19360525_30038.cpp: In function 'int main()':
0_0_19360525_30038.cpp:56:29: error: 'size' was not declared in this scope
    int j = lower_bound(b, b+size, a[i])-b+1;
                             ^
0_0_19360525_30038.cpp:63:43: error: 'size' was not declared in this scope
       printf("%d\n",b[query(root[x-1],z,1,size,root[y])-1]);
                                           ^