foo.cc: In function 'void drawing(int, int)':
foo.cc:58:5: warning: unused variable 'i' [-Wunused-variable]
 int i, j;
     ^
foo.cc:58:8: warning: unused variable 'j' [-Wunused-variable]
 int i, j;
        ^
foo.cc: In function 'int main()':
foo.cc:10:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d%d", &m, &n);
 ~~~~~^~~~~~~~~~~~~~~~
foo.cc:14:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d", &space[i][j]);
 ~~~~~^~~~~~~~~~~~~~~~~~~~

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