#include <iostream>
using namespace std;

int main(int argc, char* argv[])
{
    int a,b;
    cout<<"please input integer a and b:";
    cin>>a>>b;
    if( cin.fail() )
    {
        cin.clear();
        cin.sync();
        cout<<"input error"<<endl;
        return -1;
    }

    int result = a + b;

    if( a > 0 && b > 0 )
    {
        if( result < 0 )
            cout<<"overflow"<<endl;
    }
    else if( a < 0 && b < 0 )
    {
        if( result > 0 )
            cout<<"overflow"<<endl;
    }

    cout<<result<<endl;

    return 0;
}

how can I get more wrong information?

#include <iostream>
using namespace std;

int main(int argc, char* argv[])
{
int a,b;

cin>>a>>b;
cout<<a+b;
return 0;
}

you don't need to write mesages like .....cout<<"please input integer a and b:";.......your output must be only A+B