foo.cc: In function 'int main()':
foo.cc:17:9: error: unable to find string literal operator 'operator""sum' with 'const char [5]', 'long unsigned int' arguments
   17 |  printf("%.2d"sum);
      |         ^~~~~~~~~
foo.cc:8:8: warning: unused variable 'b' [-Wunused-variable]
    8 |  int i,b=100,num,sum;
      |        ^

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