#include
                                                        int add(int, int); /* Function prototype */
                                                        
                                                        int main()
                                                        {
                                                            int a = 4, b = 3, c;
                                                            c = add(a, b);
                                                            printf("c = %d\n", c);
                                                            return 0;
                                                        }
                                                        int add(int a, int b)
                                                        {
                                                        /* returns the value and control back to main() function */
                                                           return (a+b);
                                                        }