souvenirs.cpp:1:6: error: 'pair' in namespace 'std' does not name a template type
1 | std::pair<std::vector<int>, long long> transaction(long long m);
| ^~~~
souvenirs.cpp:1:1: note: 'std::pair' is defined in header '<utility>'; did you forget to '#include <utility>'?
+++ |+#include <utility>
1 | std::pair<std::vector<int>, long long> transaction(long long m);
souvenirs.cpp: In function 'void buy_souvenirs(int, long long int)':
souvenirs.cpp:4:5: error: 'transaction' was not declared in this scope
4 | transaction(p - 1);
| ^~~~~~~~~~~