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0_0_25090569_29065.cpp: In function 'int dij()':
0_0_25090569_29065.cpp:59:15: error: request for member 'level' in 'a[u].std::vector<_Tp, _Alloc>::operator[]<long long int, std::allocator<long long int> >(((std::vector<long long int>::size_type)i))', which is of non-class type '__gnu_cxx::__alloc_traits<std::allocator<long long int> >::value_type {aka long long int}'
    if(a[u][i].level<b[u][i]-1)
               ^