Encryption function

//Using encryption function, f(p)=p+3; find secret number produced from a given integer N
#include<stdio.h>
#include<stdlib.h>
int main(){
int p[30], num, N, b, count=0, i;
scanf("%d", &N);
b=N;
while(b!=0){
    count++;
    b/=10;
}
for(i=0;i<count;i++){
    p[i]=N%10;
    N/=10;
}
printf("Output:");
for(i=count-1;i>=0;i--){
    p[i]=p[i]+3;
    printf("%d", p[i]);
}

return 0;
}