Nth term for the given series

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#include <stdio.h>
int main()
{
    int term1=1,term2=2,sum=0;
    int itr,num;
    scanf("%d",&num);
    if(num==1 || num==2) // N= 1 or 2
        printf("%d",num);
    else // for N above 2
    {
        for(itr=3;itr<=num;itr++)
        {
            sum=term1+term2;
            term1=term2;
            term2=sum;
        }
        printf("%d",sum);
    }
    return 0;
}