poj 1006 Biorhythms

#include<stdio.h>int main(){int p, e, i, d, j, no = 1;scanf( "%d%d%d%d", &p, &e, &i, &d );while( p != -1 && e != -1 && i != -1 && d != -1 ){for( j = d + 1; j < 21252; j++ )if( ( j - p ) % 23 == 0 )break;for( ; j < 21252; j = j + 23 )if( ( j - e ) % 28 == 0)break;for( ; j < 21252; j = j + 23 * 28 )if( ( j - i ) % 33 == 0 )break;printf( "Case %d", no );printf( ": the next triple peak occurs in %d days.n", j - d );scanf( "%d%d%d%d", &p, &e, &i, &d );no++;}return 0;}