4-3

#include<stdio.h>
int main(void)
{
   int count,number;

   count=0;
   printf("Enter a number:");
   scanf("%d",&number);
   if(number<0)number=-number;
   do{
      number=number/10;
      count++;
   }while(number!=0);
   printf("It contains%d digits.\n",count);

   return 0;
}