View Compilation Error

0_0_37735170_18931.cpp: In function 'void solve()':
0_0_37735170_18931.cpp:76:15: error: 'mid' was not declared in this scope
               mid=(l+r)>>1;
               ^
0_0_37735170_18931.cpp:81:19: error: 'ans' was not declared in this scope
                   ans=mid;
                   ^