foo.c: In function 'FindMaxs':
foo.c:13:4: error: expected ';' before '}' token
    }
    ^
foo.c: In function 'main':
foo.c:22:20: warning: unused variable 'b' [-Wunused-variable]
    int n1,n2,a[n1],b[n2] ;
                    ^
foo.c:22:14: warning: unused variable 'a' [-Wunused-variable]
    int n1,n2,a[n1],b[n2] ;
              ^
foo.c:24:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n1,&n2);
  ^~~~~~~~~~~~~~~~~~~~~~