View Compilation Error

0_0_30408040_32036.cpp: In function 'int main()':
0_0_30408040_32036.cpp:77:34: error: 'ans' was not declared in this scope
                 if(it==st.end()) ans = n+1;
                                  ^
0_0_30408040_32036.cpp:78:24: error: 'ans' was not declared in this scope
                 else   ans = *it;
                        ^
0_0_30408040_32036.cpp:79:17: error: 'ans' was not declared in this scope
                 ans = min(ans,query(T[pos],k,n+1,1,n+1));
                 ^