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:10:33: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'short int*' [-Wformat=]
   scanf("%d%d",&a[i][0],&a[i][1]);
                                 ^
foo.cpp:10:33: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'short int*' [-Wformat=]
foo.cpp:12:3: error: 'c' was not declared in this scope
   c*=a[i][0];
   ^
foo.cpp:24:3: error: 'd' was not declared in this scope
   d=c/k>d?c/k:d;
   ^
foo.cpp:24:5: error: 'c' was not declared in this scope
   d=c/k>d?c/k:d;
     ^
foo.cpp:29:17: error: 'd' was not declared in this scope
  printf("%I64d",d);
                 ^