View Compilation Error

0_0_13498701_21314.cpp: In function 'int main()':
0_0_13498701_21314.cpp:11:5: error: '_int64' was not declared in this scope
     _int64   a , b ;
     ^
0_0_13498701_21314.cpp:12:16: error: 'a' was not declared in this scope
     while(cin>>a>>b)
                ^
0_0_13498701_21314.cpp:12:19: error: 'b' was not declared in this scope
     while(cin>>a>>b)
                   ^