A little useless program.

#include <stdio.h>
#include <stddef.h>

#define MAX_LEN 512

char *seps = "+=*";

int is_sep ( char ch ) {
    if ( ch == '\0' ) return 1;

    int i; for ( i = 0; seps[ i ]; i++ ) {
        if ( seps[ i ] == ch ) {
            return 1;
        }
    }

    return 0;
}

char *write_with_rotate ( char *src, char *dst ) {
    char *_src = src, *_dst = dst, *t;

    // bull shit code here!
    while ( !is_sep ( *src ) ) src++;
    while ( *src != '\0' ) {
        char *back = src;
        while ( is_sep ( *src ) ) src++;
        while ( !is_sep ( *src ) ) {
            *dst = *src;
            src++; dst++;
        } t = src; src = back; back = t; // this is swap 'src' with 'back'
        while ( is_sep ( *src ) ) {
            *dst = *src;
            src++; dst++;
        } src = back;
    } src = _src;

    while ( !is_sep ( *src ) ) {
        *dst = *src;
        src++; dst++;
    } *dst = '\0';

    return _dst;
}

int main ( int argc, char **argv ) {
    char input[ MAX_LEN ], output[ MAX_LEN ];

    fgets ( input, MAX_LEN, stdin ); input[ strlen ( input ) - 1 ] = '\0';
    printf ( "%s", write_with_rotate ( input, output ) );

    system ( "PAUSE" );

    return 0;
}