View Compilation Error

0_0_21009495_10018.cpp: In function 'int main()':
0_0_21009495_10018.cpp:56:27: error: 'building' was not declared in this scope
             scanf("%d%d",&building[i].w,&building[i].s);
                           ^
0_0_21009495_10018.cpp:59:14: error: 'building' was not declared in this scope
         sort(building,building+n,cmp);
              ^