foo.cc: In function 'int main()':
foo.cc:39:9: warning: unused variable 'len1' [-Wunused-variable]
   39 |     int len1 = Mul(n1, m1, num1);
      |         ^~~~
foo.cc:43:9: warning: unused variable 'len2' [-Wunused-variable]
   43 |     int len2 = Mul(n2, m2, num2);
      |         ^~~~
foo.cc: In function 'int Mul(int, int, int*)':
foo.cc:32:12: warning: 'len' may be used uninitialized [-Wmaybe-uninitialized]
   32 |     return len;
      |            ^~~
foo.cc:23:9: note: 'len' was declared here
   23 |     int len;
      |         ^~~
foo.cc:7:13: warning: 'len' may be used uninitialized [-Wmaybe-uninitialized]
    7 |         int len;
      |             ^~~
foo.cc: In function 'int main()':
foo.cc:44:9: warning: 'len' may be used uninitialized [-Wmaybe-uninitialized]
   44 |     int len;
      |         ^~~

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