#include <REG51.H>
sbit LED = P1^7;

void delay(void) {
    unsigned int i, j;
    for (i = 0; i < 20; i++)
        for (j = 0; j < 50; j++);
}

void main(void) {
    while (1) {
        LED = 0;
        delay();
        LED = 1;
        delay();
    }
}
