foo.cc: In function 'int main()':
foo.cc:10:7: error: 'j' was not declared in this scope; did you mean 'jj'?
   10 |   for(j=i;j>=10;j/=10)
      |       ^
      |       jj
foo.cc:12:8: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   12 |   if(nn=jj)
      |      ~~^~~

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