#include "stdafx.h"#include <stdio.h>
int main(int argc, char* argv[]){ int n; int i; int speed,time; int miles; int prev=0; scanf("%d",&n); while(n != -1) { miles = 0; prev = 0; for(i=0;i<n;i++) { scanf("%d %d",&speed,&time); miles += speed * (time-prev); prev = time; } printf("%d miles/n",miles); scanf("%d",&n); }
return 0;}
