#include <stdio.h>
#include <stdlib.h>

unsigned int getbits(unsigned int x, int p, int n) {
    return (x >> (p + 1 - n)) & ~(~0 << n);
}

int main( int argc, char** argv ) {
    unsigned int N, x;

    printf( "Inserisci numero:\t" );
    scanf( "%d", &x );

    printf( "Ti calcolero' %d mod 2^N, inserisci N:\t", x );
    scanf( "%d", &N );

    printf( "%d %% 2^%d = %d \n", x, N, getbits( x, N-1, N ) );

    return 0;
}