foo.cc: In function 'int main()':
foo.cc:8:13: error: redeclaration of 'int n'
    8 |         int n=0
      |             ^
foo.cc:4:9: note: 'int n' previously declared here
    4 |     int n;
      |         ^
foo.cc:9:25: error: expected ';' before ')' token
    9 |         for(m=2,m<=n;m++){
      |                         ^
      |                         ;
foo.cc:6:13: warning: unused variable 'i' [-Wunused-variable]
    6 |         int i,m;
      |             ^
foo.cc:7:13: warning: unused variable 't' [-Wunused-variable]
    7 |         int t=0;
      |             ^

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