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0_0_39222547_19993.cpp: In function 'int main()':
0_0_39222547_19993.cpp:5:11: error: 'scanf' was not declared in this scope
    5 |     while(scanf("%llx %llx", &a, &b) != EOF) {
      |           ^~~~~
0_0_39222547_19993.cpp:5:41: error: 'EOF' was not declared in this scope
    5 |     while(scanf("%llx %llx", &a, &b) != EOF) {
      |                                         ^~~
0_0_39222547_19993.cpp:1:1: note: 'EOF' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?
  +++ |+#include <cstdio>
    1 | int main(void)
0_0_39222547_19993.cpp:9:13: error: 'printf' was not declared in this scope
    9 |             printf("%llX\n", result);
      |             ^~~~~~
0_0_39222547_19993.cpp:9:13: note: 'printf' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?
0_0_39222547_19993.cpp:11:13: error: 'printf' was not declared in this scope
   11 |             printf("-%llX\n", -result);
      |             ^~~~~~
0_0_39222547_19993.cpp:11:13: note: 'printf' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?