View Compilation Error

0_0_25330829_26331.cpp: In function 'int main()':
0_0_25330829_26331.cpp:51:107: error: expected '}' at end of input
   {            printf("None\n");   }    else                        {             printf("%d\n",ata.top());//输出   ata.pop();//清除首栈  }
                                                                                                           ^
0_0_25330829_26331.cpp:51:107: error: expected '}' at end of input
0_0_25330829_26331.cpp:51:107: error: expected '}' at end of input
0_0_25330829_26331.cpp:51:107: error: expected '}' at end of input
0_0_25330829_26331.cpp:51:107: error: expected '}' at end of input
0_0_25330829_26331.cpp:51:107: error: expected '}' at end of input