foo.cpp: In function 'int main()':
foo.cpp:6:2: error: '_int64' was not declared in this scope
  _int64 c=1,d;
  ^
foo.cpp:6:9: error: expected ';' before 'c'
  _int64 c=1,d;
         ^
foo.cpp:13:3: error: 'c' was not declared in this scope
   c*=a[i][0];
   ^
foo.cpp:25:3: error: 'd' was not declared in this scope
   d=c/k>d?c/k:d;
   ^
foo.cpp:25:5: error: 'c' was not declared in this scope
   d=c/k>d?c/k:d;
     ^
foo.cpp:31:17: error: 'd' was not declared in this scope
  printf("%I64d",d);
                 ^