View Compilation Error

0_0_32067054_15164.cpp: In function 'int main()':
0_0_32067054_15164.cpp:101:8: error: 'st' was not declared in this scope
    add(st,i,1,-a[i].w);
        ^
0_0_32067054_15164.cpp:102:12: error: 'ed' was not declared in this scope
    add(i+n,ed,1,0);
            ^
0_0_32067054_15164.cpp:105:13: error: 'st' was not declared in this scope
  cout<<-gao(st,ed,K,2*n+2)<<endl;
             ^
0_0_32067054_15164.cpp:105:16: error: 'ed' was not declared in this scope
  cout<<-gao(st,ed,K,2*n+2)<<endl;
                ^
0_0_32067054_15164.cpp: At global scope:
0_0_32067054_15164.cpp:109:1: error: expected declaration before '}' token
 }
 ^