View Compilation Error

0_0_37474592_12069.cpp: In function 'void solve()':
0_0_37474592_12069.cpp:42:27: error: cannot convert 'std::string {aka std::basic_string<char>}' to 'const char*' for argument '1' to 'int atoi(const char*)'
             int k = atoi(s);
                           ^