A. Squats

A. Squats.cpp

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

int n;
char s[250];
int ans, cnt, nd2;

int ABS( int x )
{
	return ( x<0 ? -x : x );
}

int main( void )
{
	int i;

	while( scanf( "%d", &n ) == 1 ) {
		scanf( "%s", s );
		nd2 = n/2;

		cnt = 0;
		for( i = 0; i < n; ++i ) if( s[i] == 'x' )
			++cnt;

		ans = ABS( nd2-cnt );

		if( cnt != nd2 ) {
			if( cnt > nd2 ) {
				for( i = 0; i < n && cnt != nd2; ++i ) if( s[i] == 'x' ) {
					s[i] = 'X';
					--cnt;
				}
			} else {
				for( i = 0; i < n && cnt != nd2; ++i ) if( s[i] == 'X' ) {
					s[i] = 'x';
					++cnt;
				}
			}
		}

		printf( "%d\n%s\n", ans, s );
	}

	return 0;
}