foo.cc: In function 'int main()':
foo.cc:7:23: warning: unused variable 'b' [-Wunused-variable]
     int a[1000][1000],b[100];
                       ^
foo.cc:8:20: warning: unused variable 't' [-Wunused-variable]
     int n, m,max,s,t=0;
                    ^

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