View Compilation Error

0_0_16369438_9385.cpp: In function 'long long int DMST(long long int, long long int, long long int)':
0_0_16369438_9385.cpp:26:85: error: 'ans' was not declared in this scope
     in[edge[i].to]=edge[i].val,pre[edge[i].to]=edge[i].fr,ans2=edge[i].fr==root?min(ans,i):ans2;
                                                                                     ^