foo.cc: In function 'void bfs()':
foo.cc:19:5: error: 'st' was not declared in this scope
     st[1][1]=true;
     ^~
foo.cc:19:5: note: suggested alternative: 'tt'
     st[1][1]=true;
     ^~
     tt
foo.cc: In function 'int main()':
foo.cc:38:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
foo.cc:41:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d",&g[i][j]);
             ~~~~~^~~~~~~~~~~~~~~

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