text: 'use strict';
  
  process.stdin.resume();
  process.stdin.setEncoding('utf-8');
  
  let inputString = '';
  let currentLine = 0;
  
  process.stdin.on('data', inputStdin => {
      inputString += inputStdin;
  });
  
  process.stdin.on('end', _ => {
      inputString = inputString.trim().split('\n').map(string => {
          return string.trim();
      });
      
      main();    
  });
  
  function readLine() {
      return inputString[currentLine++];
  }
  
  /*
   * Return a count of the total number of objects 'o' satisfying o.x == o.y.
   * 
   * Parameter(s):
   * objects: an array of objects with integer properties 'x' and 'y'
   */
  function getCount(objects) {
      let count = 0;
      objects.forEach((value, index, objects) => {
          if (value.x == value.y) {
              ++count;
          }
      });
      return count;
  }
  
  
  function main() {
      const n = +(readLine());
      let objects = [];
      
      for (let i = 0; i < n; i++) {
          const [a, b] = readLine().split(' ');
          
          objects.push({x: +(a), y: +(b)});
      }
      
      console.log(getCount(objects));
  }
  