adding integers and double in c

1#include <stdio.h>
2int main() {    
3	int sum_tot = 0;
4    int num_1, num_2;    
5    printf("Please, Enter First integer: ");
6    scanf("%d", &num_1);
7    printf("\nNow Please, Enter Second integer: ");
8    scanf("%d", &num_2);
9
10    sum_tot = num_1 + num_2;      
11    
12    printf("\n%d + %d = %d", num_1, num_2, sum_tot);
13    return 0;
14}

1#include <stdio.h>
2int main(void)
3{
4	int a, b, int_sum;
5    double c, d, decimal_sum;
6    
7    printf("Enter two integers: "); 
8    scanf("%i%i", &a, &b);
9    
10    int_sum = a + b;
11  
12 	printf("Enter two decimal numbers: ");
13	scanf("%lf%lf", &c, &d);
14  
15 	decimal_sum = c + d;
16  
17  	printf("The sum of a + b is %i\nThe sum of c + d is %lf", int_sum, decimal_sum);
18  
19  	return 0;
20}  

1#include<stdio.h>
2int main() {
3int a, b, sum;
4printf("\nEnter two no: ");
5scanf("%d %d", &a, &b);
6sum = a + b;
7printf("Sum : %d", sum);
8return(0);