UVa10924.c

#include<stdio.h>
#include<ctype.h>
#include<string.h>

int letter_to_i( char c )
{
    if( isupper(c) )
        return c - 'A' + 27;
    else if( islower(c) )
        return c - 'a' + 1;
    else
        return 0;
}

int main()
{
    int prime[10005] = { 1, 0, 0 };
    int i, j;
    for( i = 2 ; i <= 10000 ; i++ )
        if( !prime[i] )
            for( j = i+i ; j <= 10000 ; j+=i )
                prime[j] = 1;
    
    char word[25];
    while( gets(word) )
    {
        int L = strlen(word);
        int sum = 0;
        for( i = 0 ; i < L ; i++ )
            sum += letter_to_i( word[i] );
        if( prime[sum] )
            printf( "It is not a prime word.\n" );
        else
            printf( "It is a prime word.\n" );
    }
    
    return 0;
}