foo.cc: In function 'int main()':
foo.cc:6:1: error: expected initializer before 'cin'
    6 | cin>>m
      | ^~~
foo.cc:5:9: warning: unused variable 'm' [-Wunused-variable]
    5 |     int m,x1,x2,x3
      |         ^
foo.cc:5:11: warning: unused variable 'x1' [-Wunused-variable]
    5 |     int m,x1,x2,x3
      |           ^~
foo.cc:5:14: warning: unused variable 'x2' [-Wunused-variable]
    5 |     int m,x1,x2,x3
      |              ^~

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