程序代码：

#include <iostream>

using namespace std;

int main()
{
    int v1,v2,v3,sum;
    cout<<"Enter three int numbers:"<<endl;
    cin>>v1>>v2>>v3;
    sum=v1+v2+v3;
    cout<<"The sum of "<<v1<<" , "<<v2<<" and "<<v3<<" is:"<<sum<<endl;
    
    return 0;
}