.slider {
width: 90%;
height: auto;
overflow: hidden;
}
.slider ul {
  display:flex;
  padding: 0;
  width: 800%;
  animation: cambio1 50s infinite;
  animation-direction: alternate;
  animation-timing-function: linear;
}
.slider li {
  width: 120%;
  list-style: none;

}
.slider img {
  width: 100%;
}
@keyframes cambio1 {
    0% {margin-left: 0;}
    10% {margin-left: 0;}
    12,5% {margin-left: -100%;}
    22,5% {margin-left: -100%;}
    25% {margin-left: -200%;}
    35% {margin-left: -200%;}
    37,5% {margin-left: -300%;}
    47,5% {margin-left: -300%;}
    50% {margin-left: -400%;}
    60% {margin-left: -400%;}
    62,5% {margin-left: -500%;}
    72,5% {margin-left: -500%;}
    75% {margin-left: -600%;}
    85% {margin-left: -600%;}
    87,5% {margin-left: -700%;}
    100% {margin-left: -700%;}
}