#include<stdio.h>int main(){ int i,j,k; int n,m; int cntin=0; int resu=9999999; int count[3000]={0}; int a[400100]; int low[3000],high[3000]; while (scanf("%d%d",&n,&m)==2) { for (i=1;i<=n;i++) scanf("%d",&a[i]); for (i=1;i<=m;i++) { scanf("%d%d",&low[i],&high[i]); count[i]=0; } resu=9999999; cntin=0; for (i=1;i<=m;i++) if (count[i]>=low[i]&&count[i]<=high[i]) cntin++; if (cntin==m) resu=0; for (i=1,j=1;j<=n;j++) { count[a[j]]++; if (count[a[j]]==low[a[j]]) cntin++; while (i<=j&&(count[a[j]]>high[a[j]]||count[a[i]]>low[a[i]])) { if (count[a[i]]==low[a[i]]) cntin--; count[a[i]]--; i++; } if (cntin==m) { if (j-i+1<=resu) resu=j-i+1; } } if (resu>n) printf("%dn",-1); else printf("%dn",resu); } return 0;}
