foo.cc: In function 'int main()':
foo.cc:7:15: warning: variable 'm' set but not used [-Wunused-but-set-variable]
     int a,b,c,m,t;
               ^
foo.cc:8:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&a,&b);
     ~~~~~^~~~~~~~~~~~~~

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