#include <iostream>using namespace std;int main(){ int a , b , c; cin >> a >> b >> c; if(a + b <= a + c && a + b <= b + c) cout << a + b << endl; else if(b + c <= a + b && b + c <= c + a) cout << b + c << endl; else if(a + c <= a + b && a + c <= c + b) cout << a + c << endl; return 0;}

This is a simple C++ program that takes three integer inputs from the user and then calculates the sum of the two smallest numbers. Here's a step-by-step explanation:

1. The program starts with the inclusion of the iostream library, which allows it to perform input and output operations.

2. The 'using namespace std;' line allows the program to use names for objects and variables from the standard library.

3. The main function is declared. This is the function that is called when the program is run.

4. Inside the main function, three integer variables a, b, and c are declared.

5. The 'cin' statement is used to take input from the user for these variables.

6. The program then checks three conditions using if-else if statements. Each condition checks the sum of two variables and compares it with the sum of the other two pairs. The condition that is true will have the smallest sum.

7. The 'cout' statement is used to print the smallest sum to the console.

8. The program then ends with a return 0 statement, which indicates that the program has run successfully.