Point out the error in the program

#include<stdio.h>
int main

Point out the error in the program

#include<stdio.h>
int main()
 {
     int a=10;
     void f();
     a = f();
     printf("%d\n", a);
     return 0;
 }
 void f()
 {
     printf("Hi");
 }

2) If int is 2 bytes wide.What will be the output of the program?

#include <stdio.h>
void fun(char**);
int main()
 {
     char *argv[] = {"ab", "cd", "ef", "gh"};
     fun(argv);
     return 0;
 }
void fun(char **p)
 {
     char *t;
     t = (p+= sizeof(int))[-1];
     printf("%s\n", t);
 }

3) What will be the output of the program?

#include<stdio.h>
int main()
 {
     int fun(int);
     int i = fun(10);
     printf("%d\n", --i);
     return 0;
 }
int fun(int i)
 {
    return (i++);
 }

4) What will be the output of the program?

#include<stdio.h>
int i;
int fun1(int);
int fun2(int);

int main()
 {
     extern int j;
     int i=3;
     fun1(i);
     printf("%d,", i);
     fun2(i);
     printf("%d", i);
     return 0;
 }
int fun1(int j)
 {
     printf("%d,", ++j);
     return 0;
 }
 int fun2(int i)
 {
     printf("%d,", ++i);
     return 0;
 }
 int j=1;

5) How many times the program will print "Study 2 Online" ?

  #include<stdio.h>
  int main()
 {
     printf("Study 2 Online");
     main();
     return 0;
 }