#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char*mmap();

#define rd_skip_line() while(*rp++!=10)
#define wt(v) {long _z=v;do*--wp=_z%10+48;while(_z/=10);}

int a[200000];

long f1(){
	char*rp=mmap(0l,1l<<25,1,2,0,0ll);
	rd_skip_line();
	char*sp=rp-1;
	long z=0;
	while(*rp){
		char*pp=sp;
		sp=rp;
		long j=0,p,r;
		while(p=*pp++,r=*rp++,r!='\n'&&r==p){
			long x=++a[j++];
			z+=x*(x+1);
		}
		--rp;
		while(*rp++!='\n'){
			a[j++]=1;
			z+=2;
		}
	}
	return z>>1;
}

void f2(long z){
	char wbuf[64],*wp=wbuf+sizeof wbuf;
	wt(z);
	write(1,wp,wbuf+sizeof wbuf-wp);
	_exit(0);
}

int main(){
	f2(f1());
	return 0;
}